I just bought a dvd/vhs combo unit to turn my old tapes into dvd's. After stuggling with it to get it to record. i was finally able to record one of the tapes on the dvd+. When i veiw it on the combo player, it works fine, but it will not play on any other dvd player i own. A message comes up saying unreadable format. Can anyone help? what am i doing wrong?