GridView display incomplete after drag an outer gridSplitter

[rui]

when drag an outer gridSplitter  the gridview  display incomplete

the step is

1.  drag the gridview's scrollbar to bottom

 2. drag up the red gridSplitter 

3. then the gridview display incomplete

my code is as follows

<Window x:Class="RadComboBoxStyling.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
        xmlns:example="clr-namespace:RadComboBoxStyling"
        Title="MainWindow"
         WindowState="Maximized">
    <Window.Resources>
        <example:AgencyViewModel x:Key="DataSource" />
    </Window.Resources>    
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="3*" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>
        <GridSplitter Height="2"
                      HorizontalAlignment="Stretch"
                      VerticalAlignment="Bottom"
                      Background="Red"
                      ShowsPreview="True" />
        <telerik:RadTabControl Grid.Row="1">
            <telerik:RadTabItem>
                <telerik:RadGridView  ItemsSource="{Binding Source={StaticResource DataSource}, Path=TestData}" />
            </telerik:RadTabItem>
        </telerik:RadTabControl>
    </Grid>
</Window>

class AgencyViewModel
    {
        public AgencyViewModel()
        {
            TestData = new DataTable();
            testData.Columns.Add(new DataColumn { ColumnName = "aa" });
            testData.Columns.Add(new DataColumn { ColumnName = "bb" });
            for (int i = 0; i < 10; i++)
            {
                testData.Rows.Add(new string[] { "testaa" + i, "testbb" + i });
            }
        }

        private DataTable testData;

        public DataTable TestData
        {
            get { return testData; }
            set { testData = value; }
        }
    }

[rui]

Delete the RadTabControl  the issue is also exist  the xaml code is as follow

<Window x:Class="RadComboBoxStyling.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
        xmlns:example="clr-namespace:RadComboBoxStyling"
        Title="MainWindow"
         WindowState="Maximized">
    <Window.Resources>
        <example:AgencyViewModel x:Key="DataSource" />
    </Window.Resources>    
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="3*" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>
        <GridSplitter Height="2"
                      HorizontalAlignment="Stretch"
                      VerticalAlignment="Bottom"
                      Background="Red"
                      ShowsPreview="True" />
        <telerik:RadGridView Grid.Row="1"
                             ItemsSource="{Binding Source={StaticResource DataSource}, Path=TestData}" />
    </Grid>
</Window>