Tom Tom navigator 5 + Ipaq

I have navigator 5 with benelux maps and I want to add gb maps, wich are already on my memory card but when I go to change the maps only benelux shows in the list. how do I add them to the program. thanx

The uk map is on the root of the card
and
in its own original named folder?

It should see it as long as the two conditions are met.

My great britain map folder is called

Great_Britain_Plus-Map

This is for the plus map.