I have used mapsource to copy a region of Europe CN 2009 NT to my micro sd card on the Etrex Legend HCx. I have also copied a portion of an unlocked TOPO map which is also registered inside of Mapsource to the card. One overwrites the other.

On the card itself I have renamed the second one to gmapsup1.img but the it is never seen by the unit.

Any ideas please?