PRISM 4, MEF, Docking

[Ubuntu]

Dear all,

I have a simple requirement which is to have two panes (in one of my pages) within the dock control.
I end up searching for a solution because the initial one didn't work:

Initial Solution:
=============================================
XAML Layout of the main page holding the other two views:

<Grid x:Name="LayoutRoot" Background="White">
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="*"/>
    </Grid.ColumnDefinitions>
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="*"/>
        <RowDefinition Height="Auto"/>
    </Grid.RowDefinitions>
    <telerik:RadDocking x:Name="designdock" Grid.Row="1" Background="Black" BorderBrush="Black">
        <telerik:RadDocking.DocumentHost>
            <telerik:RadSplitContainer x:Name="desginspliter" Orientation="Vertical">
                <telerik:RadPaneGroup x:Name="unpostedRegion"
                    <telerik:RadPane prism:RegionManager.RegionName="DailyUnPostedRegion"
                      </telerik:RadPane>
       </telerik:RadPaneGroup>
                <telerik:RadPaneGroup >
                    <telerik:RadPane x:Name="buttompane">
                        <ContentControl prism:RegionManager.RegionName="DailyPostedRegion" />
                    </telerik:RadPane>
                </telerik:RadPaneGroup>
            </telerik:RadSplitContainer>
        </telerik:RadDocking.DocumentHost>
    </telerik:RadDocking>

</Grid>

But that didn't make the views (UserControls) load or appear ...

Current Solution:
==============================================
XAML layout of the main page holding the other two views:

<telerik:RadDocking x:Name="designdock" Grid.Row="1" Background="Black" BorderBrush="Black">
    <telerik:RadDocking.DocumentHost>
        <telerik:RadSplitContainer x:Name="desginspliter" Orientation="Vertical">
            <telerik:RadPaneGroup x:Name="unpostedRegion"
                    prism:RegionManager.RegionName="DailyUnPostedRegion"
                    prism:RegionManager.RegionManager="{Binding Path=RegionManager}">
      </telerik:RadPaneGroup>
            <telerik:RadPaneGroup x:Name="postedRegion"
                    prism:RegionManager.RegionName="DailyPostedRegion"
                    prism:RegionManager.RegionManager="{Binding Path=RegionManager}">
            </telerik:RadPaneGroup>
        </telerik:RadSplitContainer>
    </telerik:RadDocking.DocumentHost>
</telerik:RadDocking>

Shell Configuration of RegionAdapter:

{
    var mapping = base.ConfigureRegionAdapterMappings();
    mapping.RegisterMapping(typeof(RadPaneGroup), this.Container.GetExportedValue<RadPaneGroupRegionAdapter>());
    return mapping;
}

The two views are inheriting the RadPane and displayed from the main page using the RegionManager.RequestNavigate method.

When I run the application I got two panes loaded.
Problem:
1- If I try to move them around I got the error.

Webpage error details

Message: Unhandled Error in Silverlight Application
Code: 4004
Category: ManagedRuntimeError
Message: System.ArgumentNullException: Value cannot be null.
Parameter name: element
   at Telerik.Windows.ArgumentVerificationExtensions.TestNotNull(Object parameter, String parameterName)
   at Telerik.Windows.Controls.ParentOfTypeExtensions.IsAncestorOf(DependencyObject element, DependencyObject descendant)
   at Telerik.Windows.Controls.Docking.FocusHelper.HasFocus(UIElement target)
   at Telerik.Windows.Controls.RadDocking.SelectActivePane(RadPane radPane)
   at Telerik.Windows.Controls.Docking.PaneGroupBase.OnGotFocus(RoutedEventArgs e)
   at System.Windows.Controls.Control.OnGotFocus(Control ctrl, EventArgs e)
   at MS.Internal.JoltHelper.FireEvent(IntPtr unmanagedObj, IntPtr unmanagedObjArgs, Int32 argsTypeIndex, Int32 actualArgsTypeIndex, String eventName)

2- If I try to navigate within the same region of any I got an error in the Rest() method of the RegionAdaptor "error of invocation ..."

What did I miss here ...
Regards

[Ubuntu]

Dear all,

I managed to get it to work, but not as expected !!
Whenever I try to navigate from the main view to the detailed one, I got a new pane(or group pane, I am not sure) created !!

I have two ways to go, I need help on this
===============================
1st way: Keep the current behavior
But I need two things here:
 1- Bind the created pane header to my viewmodel property.
 2- Be aware when the pane get closed so I can check the changes to submit/cancel changes.

2nd way: Revert to static state
In which I have a pane and prism region inside, and be able to navigate like the old way from usercontrol to another

Any thoughts