I have taken the ac3 audio from the avi file using VirtualDubMod and now trying to convert the avi file (video stream) using TMPGEnc and joining the audio and video back together at the end. The audio and video is fine and watchable but at now and again the video is a bit jerky just for a second or two. I have the correct codec installed according to Gspot and the avi file is 23.976. Any help will be most appreciated. Thanks in advance.