I am having the same problem on Windows 7 and it didn't happen on my old computer with Vista. What was the major change you made to fix it, was it changing from hardware to software mode? I guess I could try that and messing with the video card settings. I have:
Windows 7
Intel Core i7 CPU, Q 720, 1.60GHz (8 CPUs) Actually can go to 3.16GHz
4gb RAM
NVIDIA GeForce GTS 360M w/1gb RAM