updated 11:50 am EDT, Fri September 4, 2009
Discs ejected before they can run
A continuing problem with the optical drives in Mac notebooks is now preventing people from installing Snow Leopard, according to discussions on Apple's support forums. Affected systems may initially accept a disc, only to eject it without mounting. Within the problem group machines may reject all discs, only DVDs, or only some particular DVDs. The Snow Leopard upgrade is sold only on DVDs.
Proposed solutions have included checking firmware and PRAM, and/or cleaning out the interior of a drive, but only modest success has been achieved so far. The problem may moreover be independent of any particular drive model, as some Mac owners are reporting problems with replacement drives, potentially even external ones. Apple has yet to offer an official explanation for drive troubles or suggest a solution.