HDTV Issue

[AcesUp2121]

Recently received a Pioneer 50" Plasma courtesy of Stars. Notify the cable company, they bring me a new DVR HD box, hook me up and tell me I'm good to go. Go to ESPN HD for the Spurs/Jazz game tonight, and the image has the black bars across the top and bottom and really looks like it can't handle the image when they go on a fast break. Like the midcourt logo is unreadable. I'm not a television expert so I thought I would post here for any advice.