Hi- I have two 7900 GTs that when I run in SLI mode the screen will work fine for a minute of two then all of a sudden the screen will start flashing lines and become a garbled mess. After lots of screwing around I discovered that if I ALT-TAB the game and then bring it back it will run better for a while. But then it goes back to the same thing again or runs super slow. I've tested both cards separately and they seem to work fine. THis problem ONLY occurs during games, never on the desktop. Anyone have any ideas? TIA! Also, even more wierd- my computer's humming sound (the fans) seem to vacilate alot and I noticed that whenever the sound seems more "bogged down" the graphics start skipping. Anyone ever heard of such a thing? Problem with the power supply or something?