Apple released iMac Graphic FW Update 3.0 on Wednesday, a firmware update for the iMac that, “fixes a graphics issue that may cause an iMac to hang under certain conditions.” The firmware update is only for iMacs running Lion.
The update is a 482K download, and you can find it in Software Update (if you have an iMac running Lion), or you can download the standalone update from Apple’s support site.
iMac