I finally got an Apple TV today. However, I am having some AirPlay issues from my MacBook Air. Basically, the image that is being displayed on my TV is smaller than size of the TV (about a half inch border around the entire image). I have seen suggestions online that suggest turning off overscan in the Settings on the Apple TV. However, this only causes the image to be LARGER than the size of the TV. How do I get the image to take up exactly the size of my TV? The resolution in the Display preferences on my MacBook Air matches the resolution of the TV (1080p).