Apple has released a firmware update for OS 9 to protect SuperDrive-equipped iMacs from a recently reported problem found using high-speed DVD media.

The update installs firmware to the SuperDrive that addresses an incompatibility with 4x DVD-R and 2x DVD-RW media, and the 2x SuperDrive in iMac.

The update is required in order to use 4x DVD-R or 2x DVD-RW media in the iMac. It also lets users eject audio CDs that are copy protected or have mastering errors. The update is only for iMacs with 15-inch flat-panel displays.

The update is available for download.