[vtkusers] VTK windows freezes after renderer camera reset invoked from overlapping menu

[tron.thomas at frontier.com]

I'm working on a cross platform application that uses VTK and Qt.  On Windows there is a peculiar problem where on some system, after a menu has been displayed that partially overlaps a VTK window, and then that window reset its renderer's camera, only the area the menu overlapped is responsive to view changes.  Everything else in the view remains frozen.

As I said this only happens on certain systems and is specific to the Windows platform.

What could be causing this problem and how can it be resolved?