I've used one for over a year, well until recently I put my Stab back in service and I got to be honest. I never once looked at that display on the back. So I don't know if it read right or not. IMO that display was put there as an extra selling point, I don't really see where it would be of much practical use. It's not like you can see it inside while watching TV. As long as when you tell it to go to "0" and it centers up by the pointer you should be ok. Just pretend that display is not there and go from there.