About 6 months ago I created GMAPSUPP.IMG from a subset of Great Britain Topo V2 and an UNL file to unlock it using Jetmouse 1.5. This worked perfectly.
Now I tried to make a different selection of maps and used the same UNL file but my Garmin 1390T cannot unlock the map. Putting the old map in again works.
As the FID and PID are unchanged, why does the UNL file not work with the new selection? and what should I do to get it to work please?