Hard Drives won't sleep..

Question

I first installed Leopard on my machine in August 2008 and after about 15 minutes of no activity it would put my system/hard drives to sleep. I could walk in the room and wouldn't hear any sounds coming from the computer.
Earlier this week, I had to fix an issue which I had to re-install Leopard. Now the hard drives stay active when the computer is supposed to be sleeping! So this is what I found when I went to the HELP section of the Energy Saver Preferences:
If your Mac won’t go to sleep or stay in sleep, check the following:
■In Energy Saver preferences, click Sleep, and drag the slider that controls the computer’s sleep to “Never.” (If you don’t see this slider, click Sleep, or click Show Details and then click Sleep.)
Does that make sense? If my computer does not go to sleep like I want it to, why would I drag the slider to NEVER?
I used to be able to leave my computer on all day while it was sleeping and wouldn't hear a peep from it until I woke it up by dragging the mouse around or touching a key on the keyboard.

Answer 1

Follow the instructions. Moving the slider resets the setting and moving it back should get you the control. I never sleep my computers or HDs, so I can't address that issue. BTW, the preferences for the energy saver are stored in the /Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist file. One thing you can try is moving it to the Desktop (might require authorization from an admin user), restarting, and reseting the preferences via the Energy Saver prefPane since the OS should create a new one in that folder. If you can't move the one in that folder or it only makes a copy, then try moving the original to the trash and deleting it.