Sorry you're having problems. After you add the map to your device rename it while keeping the .img extension. When you add another map "after" that (and rename it as well) you should have two separate maps on the device which can individually be enabled or disabled under menu - setup map - select map.
You have to reload the map again. Not just rename the one already on the device. Hope this helps.
You have to reload the map again. Not just rename the one already on the device. Hope this helps.