I have also had a pretty good root about on line ... but without success.

Sounds to me like you've got an EPROM full of garbage data. Probably due to cal values being outside of expected limits, I should imagine.
Trouble is - if you wipe that out, will it reset to default settings to allow another attempt at re-cal?
The biomed's dilemma (and no doubt the sort of thing we have all experienced).
I would start with:- batteries out; then batteries back in. After that - well, how badly does the user need the scales?
Good Luck!
