Direct TV channels on new Sony Bravia TV

I just bought a new Sony Bravia TV. Whenever I look at the local channels or my TV streaming services, the picture fits the full screen of my tv. However, when I view a Direct tv channel it only fills up about 75% of my screen. This is true for all the Direct Tv channels. This is the same Direct Tv receiver that I have had since 2004 a model H25/500. Is it possible that this receiver is incompatible with the newer Sont tv sets? I went into the picture settings on both the Sony TV and Direct TV to switch settings but nothing changed. Also had Sony tech support to remote into my tv and they said I had all the latest updates and everything was fine with the Sony TV. Appreciate any help you can give me in this matter.