i had the same problem when i was playing it in windows xp on a dell M1530 machine (which is not designed for windows xp). But anyways, because xp was not supported, dell didnt offer any drivers, so i had to get them off the net including a graphics driver for my nvidia 8600GT GPU. I think this driver is why the game was stuttering as when i reinstalled vista on the machine and ran pes 2008, it ran perfectly without any stuttering and i could run the game at max resolution and max detail level. so in my experience, i would say your GPU driver COULD be worth considering as the problem.