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Widgets Desktop Icons

I bought a brand new iMac mid 2011, and from time to time I've get these artifacts. What could be the cause?

It looks like this when the temperature of the Graphical Diode = 77-80C, but when I was on Snow Leopard, I don't remember these artifacts. After upgrading to Lion, I can't work normally.

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migrated from Aug 13 '11 at 10:33

This question came from our site for professional and enthusiast programmers.

I guess you should return it and ask for a replacement. – slhck Aug 13 '11 at 10:45
There was a recall on the 2011 27" iMac graphics card. See here: – chris Feb 8 '14 at 20:19

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