Apple has introduced a firmware update for iMac’s equipped with either the Radeon HD 2400 XT or HD 2600 Pro graphics cards.

The iMac ATI Radeon HD Graphics Firmware Update 1.0.1 is an 848k download that requires Mac OS X 10.5.2 be installed. The company explains that installing the update improves system stability, but once again fails to provide in-depth information on the patch, leading to some conjecture it repairs a problem in which some iMacs would suffer a screen ‘freeze’, becoming unusable.

Apple warns that users installing the update should follow instructions given in the updating application. After the update has been successfully applied, the ROM version will be 113-B2250L-259.