For anyone else that is seeing this problem, I tried isolating power and ground connections to the Raduino and shortening the leads from the main board. I finally decided to try another LCD display. The first one I found was a 4x20 display -- behold that worked! No garbled characters on the display when the function button was pressed. However I noticed that the transistor on the Raduino was extremely hot! I read somewhere that this is because of the backlight on the larger display (or something) and that a trace needs to be cut. Well, I didn't want to cut the trace so I searched around for a 2x16. I found one that worked and I only had to adjust the contrast a little bit (like 1/16 of a turn).?
Anyway, this is for posterity.
73,
-Rob
N4MN
Rob Cox (N4MN)