Ok, so I've got the sikkmod installed and the hi res texture pack. I know in order to get it to work properly on Radeon cards you have to disable catalyst ai, either through a registry edit or .ini file change. Well Every time I disable Catalyst ai and start the game, the graphic are still glitched. I go out of the game and catalyst ai is turned back on! No matter how I turn it off, as soon as I load up Doom it gets turned back on. Anyone heard of this before? Know how to get around it? I also tried the rename doom3.exe trick but that doesn't work, steam just gives me an error and won't load the game. Any help would be much appreciated.