Hello, I just installed ATT in my computer. Ever since I did, the Overdrive feature has been disabled in my X1900XTX. I figure this is because the ATI HotKey Poller is turned off. Simple, I decided to create profiles for my games so the core and mem speeds up themselves when a certain video game starts running. Nevertheless, I get artifacts on screen! I'm not overclocking it over it's stock speeds (650/750). Funny thing is, if I set the frequencies to their stock using ATI Tool, everything works fine. Actually, I can take the card to 700/800 with ATI Tool with not a problem. Though ATI Tool asks for the ATI HotKey Poller to be turned on. I see some options in ATT that I don't quite understand, namely the Overclock method. What's the difference between Driver Level and Low Level? Which one is recommended? I'd appreciate if you can give me a few heads up towards succesfully OC'ing my card - or at least, to get it to run at stock speeds! Heh. Thanks in advance guys!