Video and audio out of sync - please help!

I have some .avi files that I would like to back up to disc, but when I burn them to DVD using NeroVision Express 3 the video and audio gradually get s out of sync with each other. The clips are in sync at the beginning of the clip, but are completely out within 10 - 15 minutes. I have got around this problem in the past by exporting the video clip and saving it as .mpeg 2. I have tried it with these .avi files and even they are out of sync.

Is there some other software that will either let me burn the .avi files to DVD media ensuring that the video and audio are in sync or encode them into .mpeg format?