I am having an issue getting the maps to work on my unit. i downloaded some maps on the basecamp ( Minnesota topo and bwca maps) and they show up and i can see the layer on there. i go to install the map onto the unit and my sd card and it installs successfully( i just highlighted the areas that i am going to use so i dont have to wasted space). then once that all done i go onto my etrex 20x and go to layers to enable and disable what i want and only 2 of the 4 maps i downloaded show up and the 2 that are on there do not show up on the map even when it is enabled. any thoughts?