My new Apple TV works great for everything but getting info from my own iMac. When I scroll to "computer" to watch my own videos or review pictures residing on my Mac the screen says ..... turn on Sharing. I have done this and the only time I can stream pics and vids to my Apple TV is when I physically have itunes open on my Mac. Surely this does not have to be the case. Do I really have to run downstairs turn on my Mac then run back up to watch vids and pics residing on my iMac. HELP!!!!!