Overclocking gtx275oc

[mintsauce5]

hi , i've recently got hold of a bfg gtx275oc , when i've tried to overclock it within the nvidia control panel as soon as i launch a game ( cod4 or 5 ) the graphics just freeze and i have to restart the computer , when i put the clock settings back to default its fine and everything works ok , might it possibly be that my psu doesnt have enough grunt once the card is clocked ? any ideas would be appreciated

 

[Greebo]

hAVE YOU TRIED ati TOOL AND CHECKED FOR ARTIFACTS?

 

[mintsauce5]

for some reason it wont load on my computer i keep getting errors when i try to install it