i have been trying to back up my mac. I started with ITunes but when I tried to burn a DVD it came up (eventually) with a error msg saying something along the lines of "laser realignment error". Now when I tried to read a previously burned DVD the mac just re-opens the tray after trying to read the media, but normal commercial dvd's seem to play fine. Any suggestions will be much apprieciated as me and my family have purchased a fair ammount from Itunes store. Cheers.