Do you meet t he following requirements first:
Requirements for AirPlay Mirroring in OS X Mountain Lion
An Apple TV
- Apple TV (2nd or 3rd generation) with software update v5.0 or later. See How to update Apple TV software.
Supported Macs: AirPlay Mirroring in OS X Mountain Lion takes advantage of the hardware video encoding capabilities of 2nd and 3rd Generation Intel Core processors. Hardware video encoding allows AirPlay Mirroring to efficiently deliver high frame rates while maintaining optimal system performance. The following Mac models have processors that support AirPlay Mirroring:
- iMac (Mid 2011 or newer)
- Mac mini (Mid 2011 or newer)
- MacBook Air (Mid 2011 or newer)
- MacBook Pro (Early 2011 or newer)
Hope this helps
To the best of my knowledge it is a generation 3 apple tv based on the fact that I bought it in May of 2012. Other than that I cannot tell how to determine the generation of the device. My macbook pro was purchased at the same time and I have recently upgraded to Mountain Lion OS X. Everything else on my computer mirrors just fine but when I try to play a movie, the dvdplayer application changes to a checkered screen... Any idea why this would be?