Geez, obviously no one encodes Divx here.

Virtualdub is the program to use, no doubt.

What you want to do is open the AVI, then go to video and set it to direct stream copy, then go to audio and select interleaving. Set the offset to how ever much off you believe it to be, then save the avi as a seperate file. check it and if its still off try again. if you do it alot you will get very good at it quickly..

oh yeah, only select a small piece of the film when you're testing to see if its in synch by going to a spot, pressing home, then going to a spot like thirty seconds later and pressing end... you will see a tiny blue line...

when you're done, don't forget to set the beginning and end to the beginning and end of the movie respectively...