Have finally got round to investigating the problem.\n\nRepalced ram with Crucial DDR2 667. It will now POST to 256 MHz with\nPCIE Aysnc at 114MHz. NB There is a PCI bus lock so that keeps it at\n33.3MHz anyway.\n\nDRAM timings are from SPD (makes no diff if not). These are at 255.8\nMHz and a 1:1 ratio:\n\n3,3,3,9,12\n\nWhat I think is killing the overclock potential is the Vcore - I can\nonly use Auto or High usefully (haven't tried Low). Thishas resulted\nin a Vcore pretty much the same as stock at 200MHz; 1.2v\n\nAny suggestions to unlock the potental of the E4400?