Have a 2009 27" iMac. The optical drive has been acting really crazy for the past year. It hates certain blank discs and I find myself having to switch brands and then remarkably, switch back again when the drive becomes fussy. This week, the drive started eating my blank discs. I would insert a DVD-R and upon hitting eject, the mechanisms would go into motion, but the disc would not come out. Happened with several more discs. In a way, it's good news for me. I need a new optical drive and it's to the point where I know Apple will need to replace it. I have Apple Care. Called Apple they had me reset the PRAM. That did not work. I now have an appointment to bring my iMac into the Genius Bar where I am hoping they will give me a new drive. Do they usually have replacement optical drives in stock that I can walk in there, wait about a half hour, and walk out with a brand-new installed drive?