not sure what i am doing wrong but i noticed today that my new gps doesnt have a major highway listed on it (basemap) (i have the new Etrex Venture HC) but the map software that came with it for the pc has the missing highway listed on it.....so after watching the online tutorial from garmin on how to add maps to the gps i tried it and it doesnt work!!!! i try to highlight a area of the map to and nothing happens what am i not doing right???