Recently I've been consolidating my VCD's to DVD+R and have come across a problem. I split standard VCD quality MPEG's into video and audio then convert the audio to AC3 and author with DVD Maestro.

The above process works great most of the time. The problem is that every once and a while the finished video on the DVD has some blocky jerkyness at the bottom of the frame that wasn't present in the original file. Also, if the same MPEG files are burned to CD-R the picture looks fine. I've tried re-encoding the video with TMPEG, but that doesn't fix the problem.

Any ideas?