This was a know issue. RE-entering the info will fix this. When I asked Jon about this, he says he has been chasing this bug. I think it was told to us at the Legacy Users Group that it had been found. I'd try loading the most recent software. Perhaps he or Ruday will chime in.
Update...Did some diggin in past LUG meeting notes. from Spring 2014. Not sure if this is the same issue.
16. How come the first digit in the engine number displayed on the screen when scrolling becomes garbled? Please see the photo below. I fix it with the LSU and almost instantly the first digit becomes scrambled again. What is the fix for this? (T4TT)
JZ – I hate to admit it, but this has eluded us for years. Although with Version 1.52 I have not seen this happen very often. Clearing the engine record fixes the road number. (Mike Reagan indicated that the cause of this issue has been found very recently and should be fixed in a future release.)