I have a month old 24" iMac running 10.5.2. When I try to burn a DVD, I get a message that the device can't calibrate the laser for the media. The console log shows the following... It's good quality Verbatim DVD-Rs (the media ID comes up as ID: MCC 03RG20 in System Profiler which apparently is first class media) that I get the message on. I've also tried a TDK and a Sony -R just to check and get the same message. I took two of the DVDs to an Apple Store and tried burning them. They burned without a problem in the iMac there. Anyone got any useful suggestions? I did buy it from John Lewis so am just within the 28 day return period to get a brand new iMac shipped except for the hassle of having to transfer everything and wipe it again. Trying to get hold of UK Applecare at a time when I can be in front of the iMac is proving tough!