I finally got fed up with the fact my iMac (27 inch, 2011 model 3.4 Ghz i7, OSX 10.7.1) refuses to go to sleep, even after a complete wipe and reinstall following the upgrade to Lion. I decided to boot to safe mode and identify what was preventing it sleeping. Here is what I found:
1) As you would expect, the up to date versions of Apple programs are fine and do not inhibit sleep (I won't mention them all, but I tested iTunes, iPhoto, Aperture, Mail, iCal, Address Book etc);
2) I also found the following did not cause problems: (a) Syncphotos; (b) Skype; and (c) Sophos Anti-Virus.
3) Facetab and Temperature Monitor cause sleep problems through over frequent refreshes (to be fair Marcel Bresink, who writes Temperature Monitor, states this on his website) and the refresh rate needs to be adjusted (push out hard drive monitoring on Temperature Monitor to 15 minutes and refresh on facetab to 15 minutes) to avoid sleep issues.
4) Both of (a) Windows Live Mesh; and (b) Cinch prevent my iMac from sleeping and cannot be user adjusted to remove the problem. I've logged this as issues with the respective publishers.
This is a frustrating problem that I think many software companies don't take seriously. It would be interesting if others could reply with other apps/programs that they have identified as causing Mac sleep issues.
For those being driven mad by this, you can use a program called PleaseSleep to force your Mac to sleep, but if you are using your Mac for Music through iTunes and Airplay it will drive you mad cutting songs off. Another program called Jiggler can keep your Mac awake while itunes is playing, but it leaves your screen on without a screensaver.
Thanks in advance for any responses.
Message was edited by: sgoldswo