[Stewart Vernon]

Need way more info here.

What TV? What mode is the TV in? What Dish receiver? What format/mode is the Dish receiver in? What are you outputting resolution to the TV? Is it an HDTV 16x9, HDTV 4:3, or SDTV?

 

[Stewart Vernon]

Agree with Wire Nut... the most obvious culprit to check first is the asterisk (*) button on the remote. It cycles through several zoom/grey/black bar format modes. You might be zoomed.