Please excuse this if it is obvious, but have you manually "zoomed" the input by accident?
While the remote is in "tv" mode, if you press the left and right arrows on the remote, you can change the aspect ratio of the video source. When all the way to the left, the screen is 4:3. Pushing the right arrow moves from 4:3 to 14:9 to 16:9 to ZOOM 16:9 to 16:9 up/down to Cinerama to Stretch. Pushing the left arrow on the remote will take you back down the list.\\\\\\
Make sure the remote is in TV mode (press the "tv" button) before you try changing the aspect ratio (if the remote is not in TV mode, it will not do anything).
Joe
While the remote is in "tv" mode, if you press the left and right arrows on the remote, you can change the aspect ratio of the video source. When all the way to the left, the screen is 4:3. Pushing the right arrow moves from 4:3 to 14:9 to 16:9 to ZOOM 16:9 to 16:9 up/down to Cinerama to Stretch. Pushing the left arrow on the remote will take you back down the list.\\\\\\
Make sure the remote is in TV mode (press the "tv" button) before you try changing the aspect ratio (if the remote is not in TV mode, it will not do anything).
Joe