I am having a weird graphics card issue on one of my computers. The computer has an XFX GTX 260 216. When I am playing games such as TF2 and left 4 dead 2 the computer crashes every 20 minutes or so. The weird thing is that I swapped out that card for an 8800gt and the computer runs fine. I put the GTX 260 in my other computer and that computer runs fine without any crashes on the same games. Temperature is not a problem because the GTX is running at a max of 55 C give or take a few. Both computers should have a big enough power supply, with both at 750w. Both running Windows 7. What do you think is causing the graphics card to run bad on one computer, but not the other? Thanks in advance for your help on this issue.