My graphics card is the XFX 6970 (two months old by now), and no I don't use any registry cleaner BS. I'm gonna re-install my graphics card drivers and see what happens. Thanks, I'll keep you guys posted!
BTW, I don't think that it is a hardware problem since I don't experience any problems like this, at all, when playing games like Amnesia for example, or really, any game.
As for as tweaks go, I don't remember of doing any, besides the SSD stuff.
Just thought I would let you guys know, this happens randomly and when it does happen it takes like hours to occur again..