Nice
Always remove old maps (backup first on pc) from Nuvi if you have a newer version. City Navigators, CXs or Topos.
Nuvi often wouldn't show ether new nor old ones or would give weird results.
Deselect also maps covering the same area (except small cx), choose one and deselect the others when not using them. You'll avoid some problems, not always noticeable at once or predictable.