Apple has posted a firmware update for the iMac which “fixes an issue that in rare cases may cause an iMac to hang during startup or waking from sleep.”

[ad#Google Adsense 300×250 in story]iMac Graphic FW Update 2.0 is available for download from Apple’s Web site and weighs in at a scant 699KB.

System requirements call for Mac OS X 10.6.7.

Apple does not specify which particular iMac models need this update, but fear not – if you download and run the update and your iMac isn’t affected, the firmware update will not run.