Airplay and Airplay Mirroring not working in MAC OS 10.8.3
The problem is the Macbook Air will not start an Airplay connection with the AppleTV. The Airplay Mirroring attempts to start on the MAcbook Air and then after 20 - 30 seconds it goes back to a blue screen and rescales back to the Macbook Airs native resolution. My AppleTV and 3 month old Macbook Air(10.8.3) are both up to date with all software updates. I have even restarted my Airport Express
Also, the "sound output" in system preferences will not allow me to select Airplay as a source for audio.
Airplay and AppleTV are working with all iOS devices.
Airplay worked prior to the update to 10.8.3.
OS X Mountain Lion (10.8.3)