Apple today released iMac ATI Radeon HD Graphics Firmware Update 1.0.1 for iMacs using an ATI Radeon HD 2600 Pro or ATI Radeon HD 2400 XT graphics card and OS X 10.5.2.
To complete the firmware update process, please follow the instructions in the updater application (/Applications/Utilities/iMac ATI Radeon HD Graphics Firmware Update.app). The updater will launch automatically when the Installer closes.
Boot ROM or SMC Version Information: After this update has been successfully completed, ROM version will be: 113-B2250L-259.
The update weighs in at 848 KB.