Hi,
I have the same issue as highlighted in this thread: http://www.telerik.com/community/forums/wpf/docking/control-contextmenu-in-a-docking-radpane-does-not-show-up.aspx
However, setting the ContextMenuItemTemplate to null as shown in the documentation does not work
<telerik:RadPane ContextMenuTemplate="{x:Null}">