howz it

i recently have had an OC (overclock) done however sense then when  playing games (COD4 ,Farcry2) my pc crashes not to a complete shut down but the screen goes blank and i have to turn it off. this can happen at anytime so i dont think its a heat issue,
 the temps im getting are within range on both GFX and CPU

from my research im thinking that the voltage is not high enough on the memory in the bios (0.01v) and that is causing the crashes

i would like to know if anyone has had this problem and how they fixed it and what is a safe increase on the voltage

specs:
E8200 OC 3.2ghz
8800gt OC 700 x 1000mhz
GA-P35-DS3 (motherboard) v2.1

THX

ps.i dont have the OC on GFX running all the time it only kicks in when i start a game,im also having the same issues when OC is turned off