I had this problem befor too with integrated sound on a QDI Advance 10T-A mobo when playing PainKiller, my PC kept crashing, so i got a seperate sound card and it worked fine untill i overclocked, witch increaced the FSB and it didnt like it. So if you have overclocked anything, set it back to default, but if you havn't, you need to buy a sound card.