OK I see, That is very strange. Don't really know what to say. Everything seems above board there. You didn't mention it so its worth asking are you running the latest version of your BIOS?. You've been overclocking your system do you think that may have something to do with this problem? Maybe try clearing CMOS?. Have you connected the SLI bridge to the correct connections? (I've done this myself before) Sorry if you've already tried this but it's worth asking. Keep at it bud, like most PC problems when you suss it out you'll kick yourself.