Apple has issued a firmware update to address display issues affecting many brand new 27-inch iMacs.
The update, labeled 27-inch iMac Graphics Firmware Update 1.0, is 683KB large and requires Mac OS X 10.6.2. Installation instructions are available at Apple's website.
Customers complained in support forums about display and performance issues with the 27-inch iMac shortly after its Oct. 20 release.
Via MacRumors
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Image courtesy of Apple