I’m positing this with the hope that helps someone else avoid frustration. For several months I had overscan issues displaying HDMI from my computer on my Panasonic Vierrra TH-42PZ85U. The TV always cut off the borders of the screen. I searched forever for overscan options for the TV, and even tried to write custom modelines without any success. Many posts in forums were reporting similar frustration. However I finally found a simple solution. On the TV, go to Menu->Picture->Advanced Picture->HD Size. Changing HD Size to 2 fixed the problem!