I am trying to install some of the Canada Topo Map. I have loaded the map onto my computer and now using BaseCamp as my utility program. Map install is also loaded to my computer. But when I try to pick parts of the Canada Topo, i.e. BC, Alberta and Saskatchewan I cannot pick or select it to download to my Micro Sd card on my Garmin 550t. My card is a new Sd card with 4Gig of space available. Help, any ideas? Thanks!!