I Burned a few Cd's tonight and after the fourth, I put in a new blank disc. I started the process and then itunes checked the playlist and initalized the disc, the says "finishing burning"and ejects the disc. Ann error msg then pops up and says" The attempt to burn a disc failed. The device failed to calibrate the laser power level for this media" WTF? Its a 12'' PB G4. Thanks for any help.