This post exactly explains my situation but instead of removing the Boolean value yes, I need to disable a radcombo item (please check under Rad comboBox filter2 item Show All Temporary reports).
http://www.telerik.com/forums/combobox-with-textbox-filtering 
Rad comboBox filter1:
<telerik:GridBoundColumn UniqueName="STATE_CODE" DataField="STATE_CODE" HeaderText="STATE_CODE" >
                        <FilterTemplate>
                            <telerik:RadComboBox ID="RadComboBoxSTATE_CODE" DataSourceID="SqlDataSource1" DataTextField="STATE_CODE"
                                DataValueField="STATE_CODE" Height="200px" AppendDataBoundItems="true" SelectedValue='<%# TryCast(Container,GridItem).OwnerTableView.GetColumn("STATE_CODE").CurrentFilterValue %>'
                                runat="server" OnClientSelectedIndexChanged="STATE_CODEIndexChanged">
                                <Items>
                                    <telerik:RadComboBoxItem Text="All" />
                                </Items>
                            </telerik:RadComboBox>
                            <telerik:RadScriptBlock ID="RadScriptBlock1" runat="server">
                                <script type="text/javascript">

                                    function STATE_CODEIndexChanged(sender, args) {

                                        var tableView = $find("<%# TryCast(Container,GridItem).OwnerTableView.ClientID %>");

                                        tableView.filter("STATE_CODE", args.get_item().get_value(), "EqualTo");

                                    }

                                </script>
                            </telerik:RadScriptBlock>
                        </FilterTemplate>
                    </telerik:GridBoundColumn>

Rad comboBox filter2:
   <telerik:GridBoundColumn UniqueName="report" DataField="report" HeaderText="report" >
                        <FilterTemplate>
                            <telerik:RadComboBox ID="RadComboBoxreport" DataSourceID="SqlDataSource2" DataTextField="report"
                                DataValueField="report" Height="200px" AppendDataBoundItems="true" SelectedValue='<%# TryCast(Container,GridItem).OwnerTableView.GetColumn("report").CurrentFilterValue %>'
                                runat="server" OnClientSelectedIndexChanged="reportIndexChanged">
                                <Items>
                                    <telerik:RadComboBoxItem Value="All" Text="All" />
                                    <telerik:RadComboBoxItem Value="T" Text="Show All Temporary reports" Enabled="true" />
                                </Items>
                            </telerik:RadComboBox>
                            <telerik:RadScriptBlock ID="RadScriptBlock2" runat="server">
                                <script type="text/javascript">

                                    function reportIndexChanged(sender, args) {

                                        var tableView = $find("<%# TryCast(Container,GridItem).OwnerTableView.ClientID %>");

                                        tableView.filter("report", args.get_item().get_value(), "Contains");

                                    }

                                </script>
                            </telerik:RadScriptBlock>
                        </FilterTemplate>
                    </telerik:GridBoundColumn>
Temp Report numbers start with T. Regulars do not have T.
On selecting a state, say CA, if they have temp reports, it is working fine. If CA doesn't have temporary reports, but the user chooses "Show all temp records", I get ArgumentOutofRangeException and - Selection out of range Parameter name: value error.
I am not sure where to disable the item.  It will be great if I get some help on this.

Dear Support Team,


We just started using your GanttView and we have a requirement to have multiple events or "GanttTasks" on a single line.

It appears that whenever I add a GanttTask or child to a GanttTask, it always creates a new line item for the task.

Is there anyway to represent multiple events or tasks on a single line?



Thanks in advance,

Atul Soni