I have tried to play some dvd-r disc sent from abroad and the pioneer comes up with message " cannot play disc". Yet if I try thr DVD-R in my home PC it plays perfectly. I thought it might be compatabilty problem so I got further different brands of discs with the same recording but still unable to play. The brands of discs tried are princo, ritek & TDK. All work well in PC and the recording is region code 0. Any ideas what could be stopping the play back of the DVD-R?