hi all. just got a one-in-all system SONY DAV SC5. all seems fine for now playing original DVDs. but i've also tried to play a copied DVD (a backup) and tha player accepts it, but the image and the sound freezes once every 10-20 sec or so... anyone has any ideea why this happens? is it a "piracy" protection froms SONY (if smth like this exists..) or just a low quality DVD or badly writing operation? hope anyone has any ideea. thanks in advance.