Mac OS X - Energy Saver preferences won't save

Log in as an admin, run the following commands from Terminal: 
 sudo rm /Library/Preferences/SystemConfiguration/com.apple.AutoWake.plist sudo rm /Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist sudo rm /<user>/Library/Preferences/com.apple.systemuiserver.plist 
 Reboot. The next time you set your Energy Saver preferences, the settings should stick.