I have been noticing that my machine will not go to sleep at the time its automatically set to do so (45 minutes). It will go to sleep fine on command though. The iMac will kill the display at the time interval set, but not the hard drive. I did for the heck of it try a permissions repair with no success as well as a reboot. I do not have a date when this started happening. Could this be tied to a recent update? Thanks.