Yeh i think that was my problem, i may have put a little too much on, like i said I'll try resitting it and if that doesnt work then getting an aftermarket cooler looks like the best option, but i do have the stock HSF with the heatpipes and aluminium fin and like ownage said, it should perform as well as an XP-90!
The Amish Kid: I have an Antec NeoHE PSU so it doesnt come with a fan on the bottom.