i have a problem with my superdrive where if i put in a dvd-r disc with files, i am able to copy files from the disc fine but afterwards, when i insert another disc, i am unable to copy anything else. I find that when I restart my PB, it fixes the problem but each time I put in a disc and then take it out and put in another in order to copy data from that disc, I have to restart. I just did the software update for the superdrive recently and I'm wondering whether this might be a cause. Anybody else having problems or should I go to the nearest Apple Store?