Problem with my PYE DVD recorder

[paul50K]

Recently (3 months), when I record something from satellite TV with PYE (PY90DG) and finalize it, the disk can be played by my computer and very old DVD players (such as Pioneer 343). However, when using relatively newer dvd players, it plays the audio but not the video. (it recognizes the disk is dvd though) I am quite sure the problem is not caused by the dvd players because, at least one of them, plays all other dvd-, dvd+, dvd-rw, and picture cd without any problem and the old Pioneer 343 can only play a limited dvds.
In the past, I used the same method and the disks could be played by all dvd players.
I wish someone could tell me why and give me some advice.

[paul50K]

Additional information:
I used GSpot to check the disk and the result is:
DVD "VOB" format
MPEG-2 Program Stream << {1 vid, 1 aud}
Sys Bitrate: 10080 kb/s VBR
Is that normal?