The suspected cause:

WPF 4 has an annoying issue where the webbrowser and other ActiveX control cause native controls not to draw correctly or draw under them; i suspect something similar is happening in my application.

The issue:

In the left Panel of my dockmanager i have a Webbrowser hosting a Silverlight control. To the right, i have a few tabs with panels. Trying to collapse these panels as pinned items on the right-side causes the panel to first jump away from the wall (a good distance, very ugly) before the collapse animations occurs and it hides.

Has anyone seen this before? Any suggestions?

Turning off animation?

Worst case I hope to just turn off the collapse animation and make it hide immediately when the user tries to pin the panel that would at least (I hope) avoid the ugly jump before it collapses today. But I need help to do that also, please let me know how to accomplish if its my only option.