Pop-up on AppleTV saying to turn on AirPlay, but it is on.

I have turned AirPlay on on my computer, and AppleTV, but I still receive the message to turn on AirPlay every time the AppleTV screen saver comes on. Anyone know how to shut off this annoying pop-up? I have double checked all of the settings on both and they are correct, but the pop-up won't go away. Suggestions?