I have a 276C that I have had for years. I haven't downloaded a new mapset from Mapsource in a long time. I am trying to do it, but two error messages occur. The first error message states that some of the maps that I have selected have not been unlocked for my GPS. That's odd, because I have all of North America unlocked and have used them in the past. I click download anyway and proceed with the download, which appears to take place successfully until the very end.... .... at the very end the erasing existing mapset window appears and stays on forever (as in overnight) with nothing happening. Any help would be appreciated.