Out of sync on mp4 player

[SonicFusion]

Hey all
I bought a Sumvision Sempra pro 2GB movie player yesterday. I ripped my matrix disk to my pc and it created an avi file. Now with my movie player i was given AVIConverter2.1 on a disk. When i ran matrix through it, i got a AVI film which the movie player can read and it was converted to fit the screen, all was well but as the movie went on the sound became out of sync with what people were saying. If i fast forward a few seconds then all becomes normal only to start again. This happens when i fast forward and ive just tested also happens after 20 minutes into the film give or take.
Is it down to the movie player? Or just the software?
Can anyone point me to any software that will convert the film to what i need? The player can read mpg, mp4, avi and converts to 220x176.
Any help is greatly appriciated

[Baldrick]

Please give us MORE information.

How did you convert to avi from the dvd? what tool? and especially what kind of audio did you convert to? If you use mp3 vbr you usually get sync problem when reconverting it again.

And maybe try another tool to convert directly to mp4 like nero recode.