I am having some big sync problems. I have tried the guides on this site but I'm still having trouble. Here's the deal:

-I have a SVCD movie and I want to remove the sound from it and replace it with the sound from the same movie, except its a DivX version (the sound is better).
-SVCD is 29.97fps, divx is 23.97fps (something tells me this has something to do with my problems).

The problem is a gradual desync. If I get it synced up in the beginning it will be off by roughly 1300ms at the end of the movie. I tried doing a time stretch for the difference (like the guide said), but then I just get the same desync problem.

Any suggestions?