I have set my display to sleep after 10 minutes of inactivity (see screen shot). This has worked up no problems for the life of my MBP (1 year). Now, all of a sudden the display won't sleep. The display remains on, and does not dim either. Restarting the computer causes this feature to function again...then it starts to not sleep after a a few hours (or so). What's this all about? *Edit* Obviously, the computer is undisturbed. I can leave the room for an hour and my display will still be on full strength.