3dmark score 25% lower

[monkentage]

I was trying to overclock my graphics card via the nvidia contol panel and after putting the speed up a few mhz and running 3dmark06 my computer went from 11100 to 8000. At default it is still around 8000 does anyone know what could cause the score to be so low? I've also noticed a little lag in games occasionally. The only change ive made to my system was putting a Tuniq tower on the cpu which seems ot have been a success, temps idle around 21oc.

i have a q6600 at normal speed, 4gig ram and a 8800gtx