That only appears to be an issue with some people who are running the game full-screen in Windows 7.
I had the same problems with my brandnew windows 7 pc and DirectX 11
Changing the DEP solved this problem, Barbara described how to do this in
this thread Thanx again Barbara for all your help, you're amazing
You guys are so busy right now, solving all those problems and issues with all the different systems ...
you need AND deserve a huge break after getting VV4 out!!!