This may not be a true fix, but on the TV, you should have some options to change screen settings. Things like "Zoom, Full, Pan and Scan". Start up something that has a border and then play around with those see if it helps.
My DVD player when I play some DIVX movies ends up playing them in the middle of my TV screen, and I need to use the Full option on the remote to expand it.
From some reasearch, it turns out that the upscaling in the DVD player causes this with some sources. What you are seeing may be something similar.