Humm... odd. I haven't tested on Windows 7. Is this bug %100 reproducible? I should probably just get around doing a proper death screen instead of resetting the game (like a noob). I'll just do that :)
I'll check if I can reproduce it tonight and report back. After reading someone describe a similar problem in the bugs thread, I think the game didn't freeze after all but some weird focus problem might have occurred instead.