my new computer arrived today, it came with a 128mb card, which i replaced with my own 256MB Creative ATI Radeon 9600. Its all been running fine, but when i installed some games (namely vice city and call of duty), im encountering problems. after a few minutes of play, the game locks up, the screen goes black, and in the case of call of duty, an error message was displayed - something about the card not responding. it is possible to return to windows, but the colour goes to 256. i had encountered a problem like this with a card, and it was because the computer was heating up to really high tempertures. after opening the case up, ive found that the card is warm, but nothing id classify as being the problem. theres a pretty good cooling system in the computer, so i can pretty much say its nothing to do with the cooling. any ideas?