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.

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()"

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

The issue is present in some of the themes.

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.