Your TV is 16:9 wide screen. The movies you are referring to we're filmed (so to speak, as they are animated) in anamorphic wide screen. As that is the case, there are going to be the black bars (letter box) on your TV. This is completely normal and will always be the case when the movie was filmed wider than 16:9. You should always be able to look at the back of the movie box to see the filmed aspect ratio. When the aspect ratio is wider than 16:9, expect it to be letter box.