Awesome - happy to try anything within reason = will give it a go and report back!

Edit:
OK - sorry for the delay - had a few other things on.
status is as follows.
performed the firmware update as per the instructions above.
No issues with installation
message box said "update complete"
plugged it into the laptop and checked for updates.
Garmin express said 1 update - which I performed - took just a few seconds.
however - the usual test for Swansea still came back as unknown....
despite our best efforts I don't seem to be any further forward ....

as a random idea - I remember someone telling me years ago they had bought an unbranded GPS unit(ebay i think) and then installed TomTom software on it and that it worked well for them.
is this possible with a Garmin device - as a possible last-ditch attempt - my fiance prefers my tomtom to the Garmin interface so that could be a winner