I've been pulling my hair out with this problem where I can't run any games (have tried Crysis, Trackmania Nations, HL2) with Catalyst A.I. enabled (BSoD saying the ATI driver is in an infinite loop), which basically means I can't use the 2nd GPU on the card. It works in windowed mode but that's because it's not using the 2nd core. Obviously, I can turn off CAT AI and games will run fine but performance takes a huge hit as you can imagine. Also, running 3DMark Vantage gets me a blackscreen and a reset. Here are my specs: Antec 1200 Case Intel Core 2 Quad 9550 2.83GHz 8GB DDR2 G.Skill RAM 800MHz Asus P5Q Pro mobo PowerColor 4870X2 2 Seagate 360GB SATA HDDs Corsair TX750W PSU Windows Vista 64-bit SP1 Catalyst 8.10 final Any idea what could be conflicting with the Cat. A.I.? When I try to run games with the AI enabled, I get a BSoD (driver is in infinite loop it says) and/or a blackscreen then reboot. Things I've tried: Fresh install of Vista and all updates/SP1 Updated all mobo drivers Fresh install of Catalyst 8.10 final Swapping out various DIMMs Torture test my CPU/RAM for stability I'm about to go nuts trying to figure this out. Thanks for your time and help!