Rented iTunes movie not playing on my Apple TV 2nd generation

I just downloaded a rental from iTunes this afternoon and it wouldn't play on my Apple TV. I went to my library, then to Rentals found the movie but it did not come up on my Apple TV, only on my Macbook. In the beginning, I never encountered any problems with downloads, but this is the third time I've had difficulty viewing a rental from iTunes to my AppleTV. It's so frustrating!