Too many people make the mistake of producing XviD movies with packed bitstreams. These movies work fine when played on a computer, but are very dodgy when played on standalone DVD players hooked up to televisions. Some movies with packed bitstreams will reproduce correctly on some standalone units, but in other cases the audio will be out of sync relative to the picture, often quite badly. This can be very frustrating, especially seeing as there is no need for it.
When converting a movie to XviD format, it's far better to follow the example of those who know best, and simply deselect the packed bitstream option when setting up your rip. This step greatly extends your movie's compatibility with all models of standalone player, and does so without hurting quality.
The screenshots here are from VirtualDub, but VirtualDubMod is very similar, and other programs should provide similar configuration options.
Choose Video / Compression:

Select XviD MPEG-4 Codec, then click the Configure button:

Under the XviD Configuration dialogue box, chose the more button after the Profile @ Level drop-down menu:

Deselect the Packed bitstream check-box:

When your movie has finished encoding, you can check to see that it does not have a packed bitstream by dropping it into GSpot. The report should look something like this:

Notes:
- MPEG4 Modifier can remove packed bitstreams from existing XviD or DivX movies, with varying degrees of success in terms of synchronising the soundtrack. I have found that it occasionally messes up a file's structure so much that it's no longer possible to fast-forward, rewind, or jump into the middle of the movie. Other times it works perfectly.
- If a packed bitstream movie is playing with the sound out of sync, try stopping the play for a moment. If you're lucky, you might find that when you resume play, the sound has magically caught up with the video.