Tried :

FSB 376 - error 19
FSB 400 - error 19
FSB 425 - error 19
FSB 450 - error 19

with 7,8 & 9 multis (HT & CPU) and all manner of votage variations and still no joy.

I am currently on P30 but have also tried P28 (gives a 66mhzx9 at stock lol).

I'm pretty sure it aint the chip as its 100% stable @ 375x9 but just refuses to boot anything above that even if I drop the multi.

How can I RMA a board that isn't faulty - works fine @ stock speeds and a slight overclock and clocked my c2d's upto 4ghz? IT just dosn't want to play with this quad nor my old QX (had the same FSB wall with that too). Will they accept RMA due to poor Quad overclocking?