I've had my Apple TV for about a year and only really use it for Netflix and Youtube. I recently upgraded my Early 2011 Macbook's OS to Mountain Lion and last night I noticed a strange icon in my toolbar that looked like this I clicked it and saw it said "Apple TV", and immediately my Netflix movie shut off and my TV screen was mirroring my laptop's screen. The only problem is I can't get it to work again. That icon isn't appearing in my toolbar, and my computer says it can't read my Apple TV or any other Airplay devices. Is this a common problem? I want to explore this option some more and can't seem to mirror my laptop anymore.