I agree with cmaurice, it is quite general that a PC can "read" something that various standalone devices are not able to read...
Another example is given by car players and CD-Rs: it is fairly common to have CD-Rs that are painlessly read by a PC CD-ROM drive but give a lot of skips/pops/clicks on a car player... this is because car players are often "picky" about the media.
Avoid Princo :Z media if you can. If you want to learn more about media quality, I invite you to browse through the excellent media forum.
Update: by the way, this thread is becoming quite off-topic here at the CloneDVD forum... Since it does not talk about CloneDVD at all, maybe moderators could move it directly into the media forum...
Originally posted by 4myego
Why can a PC rom play a backup DVD ok and yet do not play a different stand alone DVD players.??