Just picked up my iMac 27" from Apple Store today for DVD drive replacement. On top of a mechanical malfunction, it often times did not show up in the system report.
I didn't expect to continue to have that problem, but it is still an issue. Sometimes it shows up, sometimes it doesn't. The times it does show up, it errors out whenever I try to do any burning operations, disappears, then I can't eject the disc until it decides to populate the system report, again. Holding mouse, or eject key upon startup doesn't work.
I even wiped my drive, and installed from scratch using SD Card installation, thinking maybe some file might be corrupt, preventing the drive from being recognized. However, the problem still exist.
I'm thinking maybe a firmware issue...