hascet, lock your your PCI and PCI-Express bus speeds to 33 and 100 respectively. Depending on what motherboard you have, you might be able to go to 113mhz on the PCI-Express bus speed.
And by the way guys, for any of you overclocking video cards, bumping up the bus speed of the slot ie. PCI, AGP, PCI-Express will yield you a higher overclock
The farthest I've gone with my E6600 is 3.4, but that was on stock cooling