I was having the very annoying problem of having the edges with the menus of the GUI outside of the screen for my Panasonic and Toshiba TV's.
The solution I found for the Panasonic TV was to select: MENU > PICTURE > ADVANCED MENU > HD SIZE: 2
The default HD Size is 1 for the Panasonic TC-37LZ85X. Selecting HD Size 2 solves the problem.
I should also mention that before, I was getting no image, and it was due to the fact that the mini HDMI connector did not go deep enough into the receptacle when the Beaglebone Black is inside the Adafruit BBB Case ID 1555.
RAA