I have an iMac G5 ok, this is a problem that I originally thought concerned the discs I was using. About a month ago I tried to burn a cd using toast (ver 6.0.5) - an error message came up saying something like "burn failed" - MEDIUM ERROR. I'd just bought a new batch of CDRs - (RiData) and since it was the first burn with them I thought it was just the discs. I tried burning with iTunes and got the message "The Laser Failed to Calibrate". After trying several times with the RiData discs, sometimes they would work - the same disc would reject several times, then suddenly it would take and burn. -I got tired of dealing with this and went back to my old discs (maxell) that I've never ever had a problem with in almost 2 years - but I've been having the problem with them! -I never had any issues with DVDR until the other day - then I got two separate failures with different messages : The Drive Reported an Error Sense Key Illegal Request code: 0x30, 0x05 Cannot write medium - incompatible format and The Drive Reported an Error Hardware error code: 0x09, 0x01 Tracking Servo Failure Has anyone come across this type of thing? Thinking back to what could have caused this, the only other changes to my system prior to first experiencing these issues were installing 'handbrake' and ripping one DVD down to ipod size video... can I clean the drive? Install some kind of update? PLEASE HELP!!