Welcome to the forum, ddolds!
The channels you are having problems with, are they HD channels? If so, here is the deal:
HD channels are always 16x9. However, HD channels sometimes show SD programs formatted 4x3. In this case the station that transmits the channel has to convert the the 4x3 picture to fill the 16x9 picture. Some stations add black or grey bars on each side, others simply stretch or zoom it to avoid side bars. Those bars are part of the picture sent by the station. Unfortunately the box cannot change the geometry of HD signal. Most TV sets cannot do that either.