After trying everything I was getting ready to try to reformat, but I first decided to try my old Radeon X300 and it works perfect, I just played CSS almost 4 hours straight with it.
One article I saw about the infinite loop error said it could be anything, including a bad video card.
Thanks for the replies guys.
This will be the second EVGA 6600GT I've had to RMA, hopefully they'll be kind & honor the warranty for me, my PSU is strong enough for the card and I've never overclocked anything, my system is completely stable outside of that issue making it so frustrating.