VideoPad 2.41 and Xvid codec and Mpeg layer 3 sync problem

I use VideoPad 2.41 (I know, they have a newer version) to fix movies I play on other devices. I use AVI container because all my devices will play AVIs. I usually use MPeg4(native) with MP3(native) and these mostly do what I want. But I have run into a couple of movies where the movies would stop and start - not at the same time as the audio. The movie would play alright on the computer, but not on the devices.

So, I experimented with the other codecs available and all execpt xvid would not play on my devices. So, xvid would eliminate the start-stop problem
and IMA Adpcm for audio would play fine on my computer, but not on my devices. Xvid and mp3(native) don't work together on VideoPad. Then next option was xvid and Mpeg Layer 3, but then the audio would drift more as time went by. By ten minutes into the movie, you'd hear the voice, then their lips would move.

Is there an easy fix? It usually takes an hour with VideoPad on an hour long movie.

Any thoughts?