Use these steps if:
The AirPlay icon doesn't appear on your iOS device, or iTunes on your computer, after following instructions about how to use AirPlay or AirPlay Mirroring.
or
There are performance issues while using AirPlay streaming or AirPlay Mirroring.
From http://rss.support.apple.com/iphone
When upgrading the SMC (System Management Controller) firmware on an Intel-based Mac, you experience issues if power was interrupted during the update process, or if the firmware update installation did not work for other reasons. Issues may occur when starting up, displaying video, going to sleep, or there may be fan noise issues.
From http://rss.support.apple.com/desktopcomputers
