Im sorry to say this, if you get freezes, black screens and then game crashes or just the game running after this.. sounds like a hardware failure. What is happening is the video driver crashing due to some hardware fault. I bet you use windows vista or win 7, coz this kind of "black screens" equals to "blue screens of death "in xp. Could be also a bad driver but i really doubt it. Try removing the graphic card, clean the slot and slide it again... if you are lucky you will be ok. My gf actually does that and its coz i have some blocks of video memory damaged. I just open some crap to make sure the memory damaged gets used, then launch the game and minimize the chances of driver crash.. i will be like this until the gf explodes...btw, next time your run the game, look for small dots here and there, popping and then vanishing, textures flickering, stutters for no reason.. all that stuff may be related to a faulty hardware. You actually also want to watch the temps of your gf, maybe you are crashing just due overheating, if you dont fix it it may lead to real hardware damage. Salute.