The iMac SuperDrive Firmware Update 1.0 application installs new firmware on the SuperDrive which addresses an incompatibility with 4x DVD-R and 2x DVD-RW media, and the 2x SuperDrive in iMac. You must perform this update If you intend to use 4x DVD-R or 2x DVD-RW media in your iMac. This update also enables you to eject audio CDs that are copy-protected or have mastering errors. This update is required only for iMac models with 15" flat panel displays and an internal SuperDrive.