Could inadequate power from mu power supply to my video card cause it to not play PC games smoothly? (i.e. artifacts in polys and big walls of colors etc.)... i have a 400W Antec PSU, and it ran my 9800 Pro just fine. but after that died...i tried a x1650, and now an nVidia 7600 GS, and both are giving me those crap graphic displays...(The Nvidia does run better than the x1650 though)...any thoughts as to why?