I am using an iMac (10.6) and I want to have my playlist going until I decide to shut down. I went to energy saver and to schedule. I set it for NEVER and it still goes to sleep in about 15-20 minutes. No one, so far, has been able to to help me. I even took my Mac to the shop and left it there for 3 days. I assumed, when I picked it up, that the problem was solved. It still doesn't do what I want.