In my application I have several windows using "DockArea=Document" and two windows using "DockArea=DockLeft".
One of the "DockLeft" windows is hidden or not depending on the currently active "Document". I have implemented this behaviour by subscribing the "ActiveDocumentChanged" event. In this event handler I change the "IsHidden" property of the "DockLeft" window.
Normally this works without any problems.
If the user clicks on the "pin" icon of the "DockLeft" windows, I am getting into troubles. In such a case changing the "IsHidden" property does not change any effects in the GUI (the tab page is still invisible). When the user opens the "DockLeft" window, which is always visible, the GUI updates and shows the correct tab pages.
So there seems to be an updating problem.