When there written back there region free and have no protection so that tells you that it's nothing to do with any region free coding or anything else becuase these ones play fine. These ones will play fine on the MAC G4 with DVD Player. I have some DVD-R's that were backed up using dvd decrypter also but with ISO read and then ISO write. Your post is a few months old but did you ever get the discs to play? I'm having the same problem.
