I can insert the tapes that I have recorded myself from TV shows, etc., but any pre-recorded movie tapes, exercise tapes, etc. that I have purchased will not play, they just automatically eject. I thought it may have something to do with the tab on the tape that can be removed if you do not want a tape recorded over so I tried putting cellophane tape over the tab on the movie tapes, but that makes no difference. Any suggestions?