Sorry if this is documented somewhere but I wasn't able to find it in any of the examples or online forums or documentation.

Seems as though any child controls underneath the xamTileView/xamTilePanes arent getting initialized properly. For example:

        <igTV:XamWebTileView x:Name="MainView" BorderBrush="{x:Null}" Background="{x:Null}" Foreground="{x:Null}" MaximizedStateChanging="XamWebTileView_MaximizedStateChanging" MaximizedStateChanged="XamWebTileView_MaximizedStateChanged">

         <igTV:TilePane x:Name="SystemTile" Background="{x:Null}" BorderBrush="{x:Null}" Foreground="#FFF8F8F8" Header="System" BorderThickness="0" Style="{StaticResource sbxTilePaneStyle}" Margin="2,3,2,1" >
                <TextBlock x:Name="Test"></TextBlock>
            </igTV:TilePane>

</igTV:XamWebTileView>

The textblock Test can't be found in the startup code which is called from pages InitializeComponent() function - the following function fails/returns null:

          this.Test= ((System.Windows.Controls.TextBlock)(this.FindName("Test")));