My DCT 6416 iii, with attached PVR expander, has started having playback issues. It freezes, it goes all 'pixel' distortion. I've tried turning it all off, unplugging and restarting. It still does the same thing - it's not on every recording, it varies, sometimes it'll happen once for a few seconds, then on the next recording it'll pause for indefinite periods of time, then 'pixel' constantly none of the reverse, play or forward buttons will do anything until it starts moving again on its own. Any advice on what's going on?