You need to use the length of the output audio to determine the framerate and length of the output video. Ensure that video is set to full processing mode. You should apply any filters and compression at this time so you dont have to decompress the video again. Save your avi. If the sound goes in and out of sync during the movie it is a variable frame rate movie and you cannot fix the problem.
Crashes Try again.
Try adjusting the performance settings in Real Player's preferences. It only crashed on me when I started to fiddle with RealPlayers cpu usage settings and other things using trial and error to try and increase the framerate. Try the following. . Adjust Real Player's performance settings. Turn optimized display on.