A friend copied a dvd onto a memory stick, and I copied onto an Imation RW DVD+r 2 hour video. I can play the disc back on my
computer, however, when I try to view on my DVD player, I get an

error message - Disc error, please eject the disc. Playback feature may not be available for this disc. Why would I be able to playback on my computer, but not on my DVD player?