My previous KT7A came with WW on it. It had problems with its Northbridge and having tried WW, WZ and YH, it overclocked best with WW, though just barely. When I sent it back for another one, the new KT7A came with YH installed and a different Northbridge chip than the first one. With the new system, I had problems running WW and WZ, when I enabled Fast Command Decode combined with Enhanced CPU. Instant no-post. Leaving Fast Command Decode off, it performed okay with WW and WZ. When I put YH back in, it would allow both Fast Command Decode and Enhanced CPU features without a hitch and I could OC it a little higher. Im not sure what the deal is with the different Northbridge chips and their relation to bios revisions, but there is a definite tie-in there. The first Northbridge chip that would not OC the FSB beyond 133 and performed best with WW had a metal top on it with the printing on the metal top. It might have been a metalized sticker (hiding what?!). The new board had the conventional looking all plastic Northbridge on it, much like the Southbridge. I wonder if, in order to meet demand, exceeding supply, if Abit was using good performing non-A Northbridges and remarking them. Because the board was going back under RMA, I didn't want to see if the top of the Northbridge, was indeed metal or if it was a metalized sticker. Pull your dinky cooler off and see it your Northbridge is an all-plastic one or plastic/metal hybrid. It's a good excuse to put some AS between them anyway.