Here is what I discovered :
- if you just copy a map under the maps folder : mapsource will use it, even if the registry is not updated (I suppose that Garmin as simplifyed the thing, by just importing at each startup all the maps present in the maps folders)
- if you deinstall the map with the installer/uninstaller, everything goes back to normal, as the uninstaller clean the registry too
- if you just delete the gmap folder, and you have run PGFT, then the registry entry stay there, generating some errors in PGFT and all tools that check the registry, like mapsettoolkit
So, at this point, I will add an automatic cleanup of the registry in the next version 188.8.131.52 (comming very soon).