Did you happen to try the ABIT INSERT key reset?
Like I said, if it's a BIOS setting that is wacked, doing that reset procedure will return your BIOS to fail-safe settings which means it will run the lowest settings for everything, including CPU clock/multiplier. That should get you to a point where you can at least POST.
I know you said you 'cleared' the BIOS, but I'm not sure if you pulled the battery, closed the jumpers or did the INSERT KEY rollback to fail-safe. Sorry if you already tried that.
Computers are like women sometimes.. You need to slap them around so they become afraid of you and won't fuck up again.