iMac DVD-ROM Update for Mac

From Apple:

This update places new firmware on the DVD-ROM drive shipped in iMac DV and iMac DV Special Edition computers. It improves the iMac DV models' ability to read certain CD-ROM discs and to determine whether a disc is unreadable.

Some CD-ROM discs are created in a way that makes them difficult to read, and iMac DV and iMac DV Special Edition computers may spend a long time trying to read these discs. During that time, the iMac does not respond to the mouse or keyboard. The update improves the DVD-ROM drive's ability to read some of these discs and to determine more quickly whether they can be read.