I dropped the cpu overclock and I ended up with a slightly lower score, so it isn't that. And the card is factory OC, not mine.
They seem to be compeltely random yet consistent. I was looking on some forums and a bloke with this:
A64-3700+ Sandiego / Abit KN8-SLI / 2GB Infineon BE5 2335-1t / XFX 7800GT (469/1232mhz) / X-Fi EM / 36GB Raptor.
Got 3250, which is a fair bit lower than mine, which makwes sense as I have a better graphics card.
Yet sometimes people seem to end up with 3000+ points than me.
Weird.