I would like OverflowMode to work for all RadPaneGroup in xaml/codebehind and this be persisted through SaveLayout/LoadLayout.

For example:

<telerik:RadDocking.DocumentHost>
    <telerik:RadSplitContainer x:Name="MainContainer"
                                           Orientation="Vertical">
					<telerik:RadPaneGroup ScrollMode="Item"
                                          x:Name="GroupMainTop"
                                          OverflowMode="Scroll"
                                          ScrollViewer.HorizontalScrollBarVisibility="Auto"
                                          cal:RegionManager.RegionName="RegionMainTop"
                                          telerik:ProportionalStackPanel.RelativeSize="150, 400" />

Works, but when I do:

        private void LoadLayoutInternal(XElement xml)
        {
            using (MemoryStream stream = new MemoryStream())
            {
                xml.Save(stream);
                stream.Seek(0, SeekOrigin.Begin);
                this.Docking.LoadLayout(stream);
            }
            Dispatcher.BeginInvoke(() => FixDockProperties());
        }

The RadPaneGroup no longer has OverFlowMode Scroll

When I try to fix this in code behind, this has no effect:

        private void FixDockProperties()
        {
            // Fix diverse properties die door laden van de layout verloren zijn gegaan.
            // Dat lijkt niet te werken, ik heb Telerik gevraagd waarom dat is:
            // http://www.telerik.com/forums/overflowmode=-scroll-disappears-when-i-save-load-layout#mwEJP5eh8EG4TbNqfnd00g
            GroupMainTop.OverflowMode = Telerik.Windows.Controls.TabControl.TabOverflowMode.Scroll;
            GroupMainTop.SetValue(ScrollViewer.HorizontalScrollBarVisibilityProperty, ScrollBarVisibility.Auto);
            GroupMainTop.ScrollMode = TabControlScrollMode.Item;

This happens when the resizer is moved to max right (for example) and then the orientation is changed. 

When using the UnpinAllPanes/PinAllPanes methods of a RadPaneGroup inside the Pin/Unpin events only the clicked RadPane is pinned/unpinned. If a Dispatcher is added all the RadPane instances are pinned/unpinned but after multiple pins/unpins sometimes the unpinned RadPane Headers become selected and the AutoHideArea is not longer expanded.

The issue is present in some of the themes.

When the IsHidden property of Pane is set to true at startup the Pane is shown and immediately hidden.

Message: "Value does not fall within the expected range."StackTrace = "at MS.Internal.XcpImports.CheckHResult(UInt32 hr)   at MS.Internal.XcpImports.SetValue(IManagedPeerBase obj, DependencyProperty property, Boolean b)   at System.Windows.DependencyObject.SetValue(DependencyProperty property, Boolean b)   at System.Windows.Controls.Primitives.Popup.set_IsOpen(Boolean value)   at Telerik.Windows.Controls.InternalWindow.MultiplePopupWindowHost.PopupHostManager.ClosePopup()   at Telerik.Windows.Controls.InternalWindow.MultiplePopupWindowHost.Close()   at Telerik.Windows.Controls.WindowBase.CloseWithoutEventsAndAnimations()   at Telerik.Windows.Controls.Docking.ToolWindow.Hide()   at Telerik.Windows.Controls.RadDocking.<OnUnloaded>b__26()"

1. Create a raddocking control inside of a radwindow.
2. Add a few docks.
3. Drag a dock and drop it in a floating position.
4. Drag another dock.
5. As you drag the 2nd dock the first one disappears. It's somehow falling behind the raddocking control.