hi guys. I recently installed a PNY nvidia geforce 8600gts. PCI xpress. 675MHz clock speed. 1500Mhz RAM speed. I am wondering if it is overheating because almost everytime I play a game about 2 min in it freezes. I took the side of my case off and it stopped doing it so I kind of have a feeling it is overheating. I have 2 80mm fans. one intake. and one outtake. If you think i have a faulty heatsink im going back to bestbuy and trading it in for an ati. What is a good ATI model that is roughtly similar to this card? Thanks.