DVD Player playback problems are usually one of these:
1- Media Quality makes a difference.
2- Burning too fast causes freezing and skips on playback.
3- Burning to close to the edge of the media (Specially on cheap media causes faults near the end)
4- DVD has to be burned as a Video-DVD (AUDIO_TS and VIDEO_TS directories)
What media are you using ?
VSO Inspector, or DVDInfoPro can provide you with the Media ID.
What speed are you burning those ?
Have any of the above problems ?
Also what exact problems are you getting ?
It will start but will skip ?
Getting DISK ERROR and won't even start ?
My 2 cents...