Well made many movies and all work fine except the first one which was fine until about three weeks ago. Then I went from flask to nandub and probs. This first movie and only that one I cant play smoothly even though its the one with lowest bitrate I have done. To play it properly this is what i do. Change the refresh rate, usually the lower it is the better. Even though its at its lowest, increase the dame thing and then decrease it. Let me know if this helped. Oh if this did not work then let me know and also then try the new dirextx 8.1 648 beta