i ve just bought a panasonic portable dvd ls5 player... i have a whole collection of backed up dvd movies and i cant play them at all... all movies start to fail after 20 minutes of playback. i use a sony dru 500 a writer and ridata disks... i use dvd shrink and nero 6.0. i have read out there that this player is fully compatible with dvd-r, so im at a loss. please help