What make and model TV do you have? There is another thing called "overscan." Most all sets cut off a small percentage of the picture on all 4 sides to avoid video "noise" which can be present along the edges of the picture. Between 2 and 4% overscan is considered normal. If you have DVE or Avia, they have patterns that show how much overscan your TV has.
But, sometimes the overscan is excessive and cuts of important information. This can particularly be noticed if stations have a crawl or logo positioned very close to the bottom or side of the picture. If you're not using a zoomed setting on your TV, then it's possible your TV has excessive overscan. I believe this can be corrected to some degree by a technician or ISF calibrator who can access the service menu of your TV. Accessing the service menu should only be done by someone who knows what they are doing. Real damage can be done in the service menu.
