[MrLatte23]

Computer won't go to sleep on it's own. Sleeps for other accounts/users, from log-in window or when using apple menu, power button or cmd+opt+eject, and wakes up fine. Tried disconnecting peripherals, resetting SMC, disabling dashboard all to no avail. Setting in System Preferences > Energy Saver are proper.

Is there anything in Console, System logs or Activity Window that could tell me what's keeping it up? Not sure what to look for.

Thanks

Mac Pro OS X.4.9 - 2 X 2.66 GHz - 5 GB RAM - 2 X Hitatchi 500 GB HD, Seagate 750 GB HD - 2 X Samsung 20" widescreen LCD's - Kensington Expertmouse Trackball, Wacom Tablet, Contour ShuttlePro, CanoScan N670U scanner , Nikon CoolScan V ED scanner, Epson 320 Printer, Western Digital 200 GB firewire 400 portable HD, iSight, USB 2.0 Hub, USB 1.1 Switch.

[rehoot]

Sometimes my Mac Pro does not sleep when I use the Sleep menu command (under the apple icon on the top-left). It was related to a certain application that would not let it sleep (I forget which application was the problem). Try closing all applications and anything running in the background to experiment and find the culprit. Also look in System Preferences/Accounts/Startup Items to close all of those background applications as a test.

[rehoot]

Also look in the Console (Applications/Utilities) and click on the Logs button on the top left then the system.log line in the left bar. There should be notes in there about a demand for sleep. Note the time when you try to sleep the computer and see if you see any fishy messages.

[Xarthan]

did you try giving it some milk and cookies? j/k, does it go to sleep when you close the lid?

[MrLatte23]

Finally figured out why my Mac Pro wouldn't go to sleep... Looking in System Preferences > Accounts > Log In Items, I found a driver N124U button manager that is part of the driver set for my Canon N67U Scanner but not necessary (as far as I can tell so far).

[mac128k-1984]

I have an epson scanner and that too prevents my MacPro from sleeping. I need to turn the scanner off and that seems to solve the problem.