first off, a double post thread. second off, if i recall correctly, you have a PSU that is what, 480w? and you are running 6 case fans, a cpu fan, a 7800gtx 256mb video card, a hard drive, probably at least 2 optical drives...we told you in the other thread, you need to consider a higher wattage power supply. antec is a good brand, but i suggest you go with a 550 or a 600 like we told you in the other thread.
even if it doesnt solve the problem of stuttering, you have more of a chance of not screwing yourself over with not enough power.