The new Asus bios (0304) does the same thing on my machine, in fact it shuts down the CPU fan while the board is still lit. (kinda scary)

I played with it for a few hours last night and saw no real improvement in performance. The NB multi seems to work reliably now, the only effect I saw that would lead me to think ACC was doing something was the fact that if I set it below -6 the board wouldn't post.

Oh well, still waiting for a reply from Asus Tech. Hopefully they'll have somethng a little better to offer.