overclocked e6300 3dmark problems

[imported_Conrad]

i have my e6300 running at 7x505 on a p5b dlx wifi board(bios 0507), and when i load any 3dmark it hangs to a black screen. the overclock has passed orthos, dual superpi 32mb,etc and is rock solid running loops of pcmark05. but 3dmark black screens everytime after the first test. i am running my southbridge and northbridge at mav voltage the cpu is running at 1.45v and my memory is at 2.2v. if i lower to 7x493 it runs fine. where should i look to try and stablize this at atleast 500?

 

[OcHungry]

Your vid card may be overclocked too high, not good enough or has driver conflict.
run driverclean after uninstalling any vid driver, then install the new driver.

 

[imported_Conrad]

ok i'll give it a shot. i tired the video card at stock with the same results. maybe i should try flashing the most recent bios. don't really understand this one, i have seen alot of problems o/c'ing in my day but this is the wierdest.