iMac Core Duo “Rev A” owners are reporting what are being dubbed “growing pains” in their new systems. Details are long and arduous reading but although it appears at first to be an issue with the graphics cards (possibly heat related) there have been reports that the shipped OS 10.4.4 build number (viz. release number) may be the cause.

While appearing only in new iMac Core Duos and not effecting iMac G5s as far as anyone can tell, the error appears in the form of tearing. Intermittent graphical glitches include “patchyness”, video tearing, horizontal lines, ghosting and graphical artifacts are said to be make using FrontRow unbearable while QuickTime and Apple DVD Player seem unaffected. Oddly this issue still effects DVD playback through the FrontRow interface.

This is all suggesting an issue with the combination of Intel processors, some OS builds and FrontRow (possibly the graphics card also as it appears more in upgraded 256Mb Graphics Cards). The exact cause of this issue is unknown but there has been a website built dedicated to the topic which is full of interesting information including a home made demonstration video.

OS build numbers currently being shipped are 8G1165 and 8G1171 while the former seems to be the problem build. In addition to the website further information is available through the following Apple Discussion Forums links and the video will also be linked below. Any information, first hand experience of the issue or possible fixes would be very much appreciated.

[Update Warning: For those that have recieved the Podcasted version of the video I would like to warn you that the show notes included with the download are inaccurate. I let my fingers get the better of me yesterday and had to revise the wording of the article in relation to the build numbers. It appears the upload of the video was done prior to the change being implemented and that's entirely my fault; I apologise. For the most part it seems that the build 8G1165 is ok while build 8G1171 is the issue. I apologize for any inconvenience.]