My 2009 iMac will not go to sleep by itself. It will go to sleep when it's induced but not automatically. I have been through several Apple support documents on this issue and searched here and on Google but nothing they suggest like resetting PRAM etc works. I have been through console to see if I can find any errors and the only thing there is a couple of entries related to my Targus Bluetooth mouse. I have tried disabling and uninstalling this, updating the driver etc and it doesn't make any difference. I'm really struggling to find out what else could be causing this and would appreciate any pointers.