Bad authoring?

Damm, its been a while since I have been on here. I am having real issues. I just got an in dash DVD player for my car. i have music videos that i downloaded from here and there. I have used tmpgenc to rencode to DVD format in NTSC and the TMPG DVD Author to burn. The problem is on some of the videos they will start with no audio, run for about 5 seconds freeze for 15 or so seconds and start up again with the audio like nothing happened. I have tried different ways of doing the GOP structure, i have tried converting the files different ways but I can't get anything to work. Any ideas?