I was using my Panasonic DMR-EZ45V DVD recorder earlier today to record some old camcorder footage from my old camcoder.It was fine and playedback on the recorder. Tonight, I tried to play the DVD aswell as another one and the machine made a grinding noise and said 'unable to read'. I think this has happened before a few years ago, but was ok after that. What does it mean when that happens? I played the first part of it on my laptop after I tried it in the DVD recorder and it looked ok. Would it have ruined the disc?