What is the motorola box? Cable? no clue. Anyway, which remote are you using? The Sony's or the provider's? Mine in some cases I need to use my Toshiba TV remote and "picture size" '1', '2', '3', or '4'which is full. I can also use the provider's remote but it will just stretch or go widescreen and not bw full if I do that. I'd rather use the TV's "picture size" option.
Do you have it set up right with the initial configuration? There's a few steps to go through when first hooking it up, like resolution, aspect ratio, etc... for best PQ.