Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_3_1 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8G4 Safari/6533.18.5)
Try rebooting your iPhone or apple tv. Not sure if others have had similar issues but my AirPlay seems picky sometimes. Sometimes the icon won't even appear. Reboot usually solves