Help guys i'm puzzled. i have the following, P4 2.4c abit AI7 Corsair TwinX 1024-4400C25, 4x512mb i can clock the fsb for the cpu up to 260 no problem, but only on a 3:2 divider, northbridge is locked at 800, pci/agp 33/66. if i try and go to 5:4 Then i struggle getting anything over 250 stable. 1:1 is just a joke. I thought this memory should be able to run275 fsb no problem? so why does it seem to be the limiting factor. DDRv have tried 2.7, 2.8, 2.9, 2.95 and 3.0v all without success. timings are 3-4-4-8 (so pretty lose?) Any ideas? is it because the NB is locked?