[Kevin]

There might be a "zoom" button on one of your remotes. It sounds like you have your view set to some sort of a zoom, which as DS said, lets you fill up the whole screen when watching low-def broadcasts.

If there's no zoom button, the zoom function is buried somewhere in your menu. What model cable box do you have? If you can a .pdf of the user's manual (should be available on the manufacturer's website), you should be able to figure out where the zoom feature is and how to turn it off.