Installed Detonator 6.50 drivers (newer ones cause issues with Midtown Madness 2) for my TNT2 Series TNT2 Vanta 16MB and ViperV550, and the cards no longer overheat. 105MHz core and 115MHz memory on the Viper V550 running a batch 3DMark99 set from 640x480 to 1280x1024 16-32bit without overheating+locking up is a first.