Hi, After upgrading to Lion OS, the fan of my iMac 27 went crazy. I installed the iStat Pro, and it said the CPU temp was 126c (or 259f). I closed all tasks and the CPU was at 98-99% idle. I restarted the iMac and the problem remained the same. I never had any problem with SL for more than 7 months before upgrading to Lion. I bought the iMac in Jan this year. Should I take the iMac to the Apple store? Has anyone experienced the similar problem? Anyway, I don't think the temp read is correct. 126c is ridiculous and the chassis is cool. Thanks.