I've been running two Radeon HD 7900's since my original build in January, mostly without a hitch. (Had to learn that crossfire does not work in windowed gameplay) Recently had a pop-up window for Catalyst update and figured why not, might be some valuable new features. (Big Mistake). Install froze and shut down my GPU's. Hard restart in safe mode, removed GPU drivers, rebooted and installed the most previous drivers prior to the update. Everything is back to normal except that crossfire does not kick in when I play WOW. I have crossfire enabled, and even set up a profile for wow 64.exe (which I never had to do before). Nothing. Yes Blizzard has done some recent patches, but crossfire was still working before the update debacle. I have even gone as far as to remove the drivers again, pull out the GPU's and reinstall them individually with the previous drivers. Am I missing a setting somewhere? Is this a Blizzard/AMD conflict? Have I shifted into an alternate universe bent on feeding me a never ending train of puck-like frustration?