I've been using Win 7 64-bit since the beta and no issues at all - until I installed SP1. Now I get constant lockups and it seems to be related to the video driver about 50% of the time. I've done a clean install of the latest driver, tried removing SP1, done a system restore to before SP1 (clean driver install after that too) and nothing seems to work. I'm thinking I'll have to reformat (which I really don't want to do). Any ideas on how to fix this other than reformatting?