I'm trying to use an existing internal WPF application (I do have access to the source), but it was developed on XP and I'm using Windows7 64-bit. When I click (for instance) the File menu, 90% of the time I see no drop-down menu at all. The menu still exists - I can use the arrow keys to navigate up and down and choose an option if I happen to know the order of the options, but nothing renders at all. The other 10% of the time, the menu or some portion of it DOES render, but as I move the cursor up and down I get graphical corruption or disappearing options until I end up back at the "no menu is visible at all" state. This is also true of combo boxes within the application - they show no data when I drop them down, but I can arrow down and choose an entry. Microsoft has some advice about WPF rendering issues here but none of these steps has helped with my issue.