I recently flashed my sapphire x1800xt to the new pe bios. Sometimes it happens and sometimes it doesn't, but after a while the screen may artifact, but not freeze and I have to exit out of the game and restart. Is this a heat problem? Is there a fan controller program to change the fan speed to keep the card cooler. Would resetting the heatsink with arctic silver 5 help? Sould I up the voltage a little maybe. Any suggestions?