This problem so far happened to 2 divx movies I have encoded. The movie plays fine and the audio is in sync but as I am watching the movie, the movie suddenly becomes blocky for like a few seconds and then the movie becomes out of sync for the rest of the movie. The problem I figured is that the divx file has something wrong with it. The divx becomes blocky at exactly the same time as the mpeg but the divx is still in sync after the second of blockyness. The mpeg becomes out of sync. I have check for bad frames using vdub but it says there are no bad frames. The movies I am talking about are Fast and the Furious and Behind Enemy Lines. If anyone else has this problem or know how to solve it please respond.