screen is stretched

I just bought an new Apple TV and connected using component video to my plasma screen. Everything works fine, but the content of what is displayed is stretched or zoomed (ie I can't see the entire image because the edge of the images are beyond the edge of the screen like the image was zoomed). This happens with both content and even the Apple TV menus. I have a second older Apple TV when I connect to the same display looks fine. Video setting on both is 1080i HD. Is there a setting I'm missing that is zooming the displayed image? Or is there something wrong with this box? I already tried a factory restore with the same result and have the latest software installed. Thanks for you help.