Do this to test the map: Copy only your zumo's gmapprom.img file onto a clean SD card in a Garmin folder and re-name it gmapsupp.img only [x:\Garmin\gmapsupp.img]. Run [Only registered and activated users can see links. ] on gmapsupp.img to unlock it directly on the card.
As with unlocked maps on CF card for 2006-2008 GWs you may find search by POI is disabled. I've no experience with the later model Navi units with SD card though sorry.