Flash to the 0426 bios, get the latest RAID drivers (if you are using it), reformat and reinstall with barebones as mentioned.
Look
here for more info specific to the KK266(R).
Try a different IDE cable also. Are you using the one that came with the board? I say that because some cables made my system goofy.
Did you F6 and load the RAID drivers during install?
or (from the FAQ)
One Drive on Raid?
Set your CDRW/DVD on the primary channels. Put the HD as master on the first RAID channel.
Boot up, when you see the RAID screen press the key to go into the Raid Bios. Stripe the single drive as an array. It will know you have a single drive but will treat is as an array.
Then in Bios, set First Boot Device to RAID.
Good luck. Sweet system.