My Mac Pro used to be able to go to sleep by setting the Energy Saver settings to automatically sleep after so many minutes. It no longer sleeps at all on it's own. Lemme explain. If I put my computer to sleep with the Apple Menu, or Power Button or any other manual method of sleeping my computer, it works but, if I leave it to sleep on it's own only the screen will go black. When I move my mouse, the screen will instantly come back on as if only the screen was sleeping. I know what a normal sleep sounds like... I'd hear a few clicks and hard disk spin downs and then my screen would go black but, it does not do that. To prevent a bunch of people asking the "Have you tried...?" questions, I'll go ahead and list the things that I have already tried and failed. 1. Repaired permissions 2. Unplugged any external gadget (USB and FireWire) 3. Tried a brand new user 4. Tried Restarting (Hey, couldn't hurt to just Restart) 5. Checked for weird login items (Only EyeTV Helper which has been there the whole time even before the sleep problem) 6. Made sure my software was up to date (latest security and OS Updates) 7. Booted into "Safe Mode" 8. Checked Activity Monitor for any strange processes running 9. Checked for scanner software (Couldn't find it) 10. Tried switching the Mighty Mouse to the right keyboard USB port 11. Tried un-mounting all hard drives (except for boot drive) I can't think of anything else to try. I can't believe that Safe Mode or a new user couldn't clear the problem. Has anyone else had this problem? I'm running Mac OS 10.4.9 on a Mac Pro with 3GB of (working) RAM and 3 internal SATA hard drives and 2 internal SuperDrives.