RadGridView: ColumnGroup & Tabbing issues

[Adam]

Hello Telerik - Im back to spoil your day!

I am having issues with the custom background colour I have implemented within my * Theme (see attached image).
It seems that the GroupColumnHeaders that are implemented whilst not currently in the screen-view are not rendering properly for some reason. Am I being a 'numpty and missing something within my Theme again (can post code if required) ?

                             <telerik:RadGridView x:Name="WagesGridView"
                                     Grid.Row="1"
                                     Grid.Column="0"
                                     AutoGenerateColumns="False"
                                     AlternationCount="2"
                                     AllowDrop="True"
                                     AlternateRowBackground="White"
                                     Background="AliceBlue"
                                     CanUserSelect="True"
                                     CanUserDeleteRows="False"
                                     CanUserInsertRows="False"
                                     CanUserResizeColumns="True"
                                     CanUserReorderColumns="False"
                                     EditTriggers="CellClick"
                                     HorizontalGridLinesBrush="SlateGray"
                                     IsFilteringAllowed="True"
                                     ItemsSource="{Binding Data}"
                                     RowIndicatorVisibility="Collapsed"
                                     RowHeight="26"
                                     SelectedItem="{Binding Path=SelectedWagesContainer}"
                                     EnableColumnVirtualization="True"
                                     EnableRowVirtualization="True"
                                     SelectionMode="Single"
                                     SelectionUnit="FullRow"
                                     ShowColumnFooters="False"
                                     ShowGroupPanel="False"
                                     ShowColumnHeaders="True"
                                     VerticalGridLinesBrush="Transparent">
                    <telerik:RadGridView.Resources>
                        <temp:EmployeeNoSelector x:Key="EmpNoSel"/>
                        <DataTemplate x:Key="EmployeeNumber">
                            <TextBlock HorizontalAlignment="Stretch"
                                       VerticalAlignment="Stretch"
                                       Margin="1"
                                       Text="{Binding Path=EmployeeData.EmployeeNo}"/>
                        </DataTemplate>
                        <DataTemplate x:Key="EmptyEmployeeNumber">
                            <TextBox HorizontalAlignment="Stretch"
                                     VerticalAlignment="Stretch"
                                     Margin="1"
                                     Text="{Binding Path=EmployeeData.EmployeeNo, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                     MaxLength="20"
                                     PreviewTextInput="WholeNumericChecking"/>
                        </DataTemplate>
                        <temp:EmployeeNameSelector x:Key="EmpNameSel"/>
                        <DataTemplate x:Key="EmployeeName">
                            <TextBlock HorizontalAlignment="Stretch"
                                       VerticalAlignment="Stretch"
                                       Margin="1">
                                <TextBlock.Text>
                                    <MultiBinding StringFormat="{}{0} {1} {2}">
                                        <Binding Path="EmployeeData.FirstInitial"/>
                                        <Binding Path="EmployeeData.SecondInitial"/>
                                        <Binding Path="EmployeeData.Surname"/>
                                    </MultiBinding>
                                </TextBlock.Text>
                            </TextBlock>
                        </DataTemplate>
                        <DataTemplate x:Key="EmptyEmployeeName">
                            <DockPanel LastChildFill="False" HorizontalAlignment="Stretch">
                                <TextBox HorizontalAlignment="Stretch" HorizontalContentAlignment="Center" VerticalAlignment="Stretch"
                                         Margin="1" Text="{Binding Path=EmployeeData.FirstInitial, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                         Width="20"  MaxLength="1"/>
                                <TextBox HorizontalAlignment="Stretch" HorizontalContentAlignment="Center" VerticalAlignment="Stretch"
                                         Margin="1" Text="{Binding Path=EmployeeData.SecondInitial, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                         Width="20" MaxLength="1"/>
                                <TextBox HorizontalAlignment="Stretch" Padding="4 0 0 0" VerticalAlignment="Stretch"
                                         Margin="1" Text="{Binding Path=EmployeeData.Surname, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                         MinWidth="106" MaxLength="50"/>
                            </DockPanel>
                        </DataTemplate>
                        <temp:LastContractSelector x:Key="LastConSel"/>
                        <DataTemplate x:Key="LastContract">
                            <TextBlock HorizontalAlignment="Stretch"
                                       VerticalAlignment="Stretch"
                                       Margin="1"
                                       Text="{Binding Path=EmployeeData.LastContract}"/>
                        </DataTemplate>
                        <DataTemplate x:Key="EmptyLastContract">
                            <TextBox HorizontalAlignment="Stretch"
                                     VerticalAlignment="Stretch"
                                     Margin="1"
                                     Text="{Binding Path=EmployeeData.LastContract, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                     MaxLength="12"/>
                        </DataTemplate>
                    </telerik:RadGridView.Resources>
                    <telerik:RadGridView.ColumnGroups>
                        <telerik:GridViewColumnGroup Name="Employee" Header="Employee"/>
                        <telerik:GridViewColumnGroup Name="Saturday" Header="Saturday"/>
                        <telerik:GridViewColumnGroup Name="Sunday" Header="Sunday"/>
                        <telerik:GridViewColumnGroup Name="Monday" Header="Monday"/>
                        <telerik:GridViewColumnGroup Name="Tuesday" Header="Tuesday"/>
                        <telerik:GridViewColumnGroup Name="Wednesday" Header="Wednesday"/>
                        <telerik:GridViewColumnGroup Name="Thursday" Header="Thursday"/>
                        <telerik:GridViewColumnGroup Name="Friday" Header="Friday"/>
                        <telerik:GridViewColumnGroup Name="Other" Header=""/>
                        <telerik:GridViewColumnGroup Name="Subsistence" Header="Subsistence"/>
                        <telerik:GridViewColumnGroup Name="Fares" Header="Fares"/>
                        <telerik:GridViewColumnGroup Name="Overtime" Header="Overtime"/>
                        <telerik:GridViewColumnGroup Name="SickPay" Header="Sick Pay"/>
                        <telerik:GridViewColumnGroup Name="Misc" Header="Misc"/>
                        <telerik:GridViewColumnGroup Name="Finch" Header="Finchpalm"/>
                    </telerik:RadGridView.ColumnGroups>
                    <telerik:RadGridView.Columns>
                        <telerik:GridViewDataColumn Header="" ColumnGroupName="Employee" MinWidth="26" Width="26" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <Button Style="{StaticResource FlatButton}" Height="20" Width="20"
                                            ToolTip="Add new record." Cursor="Hand"
                                            Visibility="{Binding Path=EmptyRecord, Converter={StaticResource BoolVisi}}"
                                            Command="{Binding AddRecordCommand}"
                                            PreviewMouseDown="PreviewClickOnMainGridButton">
                                        <Image Source="/WagesTimesheetApp;component/Resources/Images/add.png" Height="16" Width="16"/>
                                    </Button>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>

                        <telerik:GridViewDataColumn Header="Emp. No." ColumnGroupName="Employee" MinWidth="85" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="True" ShowFilterButton="True" IsFilterable="True"
                                                    CellTemplateSelector="{StaticResource EmpNoSel}"
                                                    DataMemberBinding="{Binding Path=EmployeeData.EmployeeNo}"/>
                        <telerik:GridViewDataColumn Header="Name" ColumnGroupName="Employee" MinWidth="160" Width="*" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="True" ShowFilterButton="False"
                                                    CellTemplateSelector="{StaticResource EmpNameSel}"
                                                    DataMemberBinding="{Binding Path=EmployeeData.Surname}"/>
                        <telerik:GridViewDataColumn Header="Last Contract" ColumnGroupName="Employee" MinWidth="105" EditTriggers="None"
                                                    ShowDistinctFilters="True" ShowFieldFilters="False" ShowFilterButton="True"
                                                    CellTemplateSelector="{StaticResource LastConSel}"
                                                    DataMemberBinding="{Binding Path=EmployeeData.LastContract}"/>
                        <telerik:GridViewDataColumn Header="" ColumnGroupName="Employee" MinWidth="26" Width="26" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <Button Style="{StaticResource FlatButton}" Height="18" Width="18"
                                            ToolTip="View Employee data" Cursor="Hand"
                                            Visibility="{Binding Path=EmptyRecord, Converter={StaticResource RevBoolVisi}}"
                                            Command="{Binding OpenEmployeeDataCommand}"
                                            PreviewMouseDown="PreviewClickOnMainGridButton">
                                        <Image Source="/WagesTimesheetApp;component/Resources/Images/information.png" Height="16" Width="16"/>
                                    </Button>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>

                        <telerik:GridViewDataColumn Header="Hours" ColumnGroupName="Saturday" MinWidth="60" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.SaturdayHours}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.SaturdayHours, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                        <telerik:GridViewDataColumn Header="Indicator" ColumnGroupName="Saturday" MinWidth="60" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.SaturdayIndicator}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="2" TextAlignment="Center"
                                             Text="{Binding Path=TimesheetData.SaturdayIndicator, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             CharacterCasing="Upper"
                                             PreviewTextInput="AlphaNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>

                        <telerik:GridViewDataColumn Header="Hours" ColumnGroupName="Sunday" MinWidth="60" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.SundayHours}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.SundayHours, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                        <telerik:GridViewDataColumn Header="Indicator" ColumnGroupName="Sunday" MinWidth="60" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.SundayIndicator}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="2" TextAlignment="Center"
                                             Text="{Binding Path=TimesheetData.SundayIndicator, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             CharacterCasing="Upper"
                                             PreviewTextInput="AlphaNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>

                        <telerik:GridViewDataColumn Header="Hours" ColumnGroupName="Monday" MinWidth="60" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.MondayHours}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.MondayHours, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                        <telerik:GridViewDataColumn Header="Indicator" ColumnGroupName="Monday" MinWidth="60" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.MondayIndicator}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="2" TextAlignment="Center"
                                             Text="{Binding Path=TimesheetData.MondayIndicator, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             CharacterCasing="Upper"
                                             PreviewTextInput="AlphaNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>

                        <telerik:GridViewDataColumn Header="Hours" ColumnGroupName="Tuesday" MinWidth="60" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.TuesdayHours}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.TuesdayHours, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                        <telerik:GridViewDataColumn Header="Indicator" ColumnGroupName="Tuesday" MinWidth="60" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.TuesdayIndicator}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="2" TextAlignment="Center"
                                             Text="{Binding Path=TimesheetData.TuesdayIndicator, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             CharacterCasing="Upper"
                                             PreviewTextInput="AlphaNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>

                        <telerik:GridViewDataColumn Header="Hours" ColumnGroupName="Wednesday" MinWidth="60" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.WednesdayHours}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.WednesdayHours, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                        <telerik:GridViewDataColumn Header="Indicator" ColumnGroupName="Wednesday" MinWidth="60" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.WednesdayIndicator}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="2" TextAlignment="Center"
                                             Text="{Binding Path=TimesheetData.WednesdayIndicator, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             CharacterCasing="Upper"
                                             PreviewTextInput="AlphaNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>

                        <telerik:GridViewDataColumn Header="Hours" ColumnGroupName="Thursday" MinWidth="60" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.ThursdayHours}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.ThursdayHours, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                        <telerik:GridViewDataColumn Header="Indicator" ColumnGroupName="Thursday" MinWidth="60" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.ThursdayIndicator}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="2" TextAlignment="Center"
                                             Text="{Binding Path=TimesheetData.ThursdayIndicator, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             CharacterCasing="Upper"
                                             PreviewTextInput="AlphaNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>

                        <telerik:GridViewDataColumn Header="Hours" ColumnGroupName="Friday" MinWidth="60" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.FridayHours}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.FridayHours, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                        <telerik:GridViewDataColumn Header="Indicator" ColumnGroupName="Friday" MinWidth="60" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.FridayIndicator}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="2" TextAlignment="Center"
                                             Text="{Binding Path=TimesheetData.FridayIndicator, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             CharacterCasing="Upper"
                                             PreviewTextInput="AlphaNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>

                        <telerik:GridViewDataColumn Header="Paid Hours" ColumnGroupName="Other" MinWidth="80" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.PaidHours}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.PaidHours, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                        <telerik:GridViewDataColumn Header="GT/TT" ColumnGroupName="Other" MinWidth="80" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.GTTTHours}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.GTTTHours, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                        <telerik:GridViewDataColumn Header="Total Hours" ColumnGroupName="Other" MinWidth="80" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.TotalHours}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.TotalHours, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>

                        <telerik:GridViewDataColumn Header="Subs" ColumnGroupName="Other" MinWidth="80" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.Subs}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.Subs, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                        <telerik:GridViewDataColumn Header="Bonus" ColumnGroupName="Other" MinWidth="80" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.Bonus}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.Bonus, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>

                        <telerik:GridViewDataColumn Header="Taxable" ColumnGroupName="Subsistence" MinWidth="70" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.TXSubsistence}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.TXSubsistence, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                        <telerik:GridViewDataColumn Header="Tax Free" ColumnGroupName="Subsistence" MinWidth="70" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.TFSubsistence}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.TFSubsistence, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>

                        <telerik:GridViewDataColumn Header="Taxable" ColumnGroupName="Fares" MinWidth="70" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.TXFares}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.TXFares, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                        <telerik:GridViewDataColumn Header="Tax Free" ColumnGroupName="Fares" MinWidth="70" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.TFFares}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.TFFares, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>

                        <telerik:GridViewDataColumn Header="Taxable" ColumnGroupName="Overtime" MinWidth="70" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.TXOvertime}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.TXOvertime, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>

                        <telerik:GridViewDataColumn Header="Taxable" ColumnGroupName="SickPay" MinWidth="70" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.TXSickPay}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.TXSickPay, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>

                        <telerik:GridViewDataColumn Header="Taxable" ColumnGroupName="Misc" MinWidth="70" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.TXMiscPay}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.TXMiscPay, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                        <telerik:GridViewDataColumn Header="Tax Free" ColumnGroupName="Misc" MinWidth="70" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.TFMiscPay}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.TFMiscPay, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>

                        <telerik:GridViewDataColumn Header="Holiday Taken" ColumnGroupName="Other" MinWidth="90" EditTriggers="None"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.HolidayTaken}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.HolidayTaken, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="WholeNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>

                        <telerik:GridViewDataColumn Header="Std. Shifts" ColumnGroupName="Finch" MinWidth="80" EditTriggers="None" IsVisible="False"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.StandardShifts}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.StandardShifts, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                        <telerik:GridViewDataColumn Header="Ext. Shifts" ColumnGroupName="Finch" MinWidth="80" EditTriggers="None" IsVisible="False"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.ExtendedShifts}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.ExtendedShifts, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                        <telerik:GridViewDataColumn Header="Stand Down" ColumnGroupName="Finch" MinWidth="80" EditTriggers="None" IsVisible="False"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.StandDownShifts}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.StandDownShifts, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                        <telerik:GridViewDataColumn Header="Expenses TX" ColumnGroupName="Finch" MinWidth="80" EditTriggers="None" IsVisible="False"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.TXExpenses}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.TXExpenses, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                        <telerik:GridViewDataColumn Header="Expenses TF" ColumnGroupName="Finch" MinWidth="80" EditTriggers="None" IsVisible="False"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.TFExpenses}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.TFExpenses, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                        <telerik:GridViewDataColumn Header="Back Pay" ColumnGroupName="Finch" MinWidth="80" EditTriggers="None" IsVisible="False"
                                                    ShowDistinctFilters="False" ShowFieldFilters="False" ShowFilterButton="False" IsFilterable="False"
                                                    DataMemberBinding="{Binding Path=TimesheetData.BackPay}">
                            <telerik:GridViewDataColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox HorizontalAlignment="Stretch"
                                             VerticalAlignment="Stretch"
                                             Margin="1" MaxLength="6"
                                             Text="{Binding Path=TimesheetData.BackPay, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}"
                                             PreviewTextInput="DecimalNumericChecking"/>
                                </DataTemplate>
                            </telerik:GridViewDataColumn.CellTemplate>
                        </telerik:GridViewDataColumn>
                    </telerik:RadGridView.Columns>
                </telerik:RadGridView>

Also; I am having issues when tabbing between cells (or rather cell content). When I get to the edge of the visible part of my RadGridView, the focus is set back to the first cell visible, on the next line instead of the next cell (which sits outside of the visible area - same line).
I believe the two issues are linked some way, so I think it must be something I have missed.

Thanks in advance!
    

[Pavel Pavlov]

Hello Adam ,

Regarding the problem with tabbing - please try to turn off the horizontal virtualization of RadGridView.(RadGridView.EnableColumnVirtualization = false; )This should fix the problem .

Regarding the problem with common headers - can you help us reproduce the issue here? Please open a support ticket and attach a small runnable project exposing the issue. I am sure we can think of some solution, fix or workaround once we are able to reproduce the issue here.

Regards,
Pavel Pavlov
the Telerik team

[Adam]

Hello Pavel,

    Thank you for the reply.
    I managed to sort the tabbing issue - and even realised my failure with Virtualisation.
    I shall create a ticket now.

        Thanks.