Find the map version in your gps
press the suitcase(third icon at the bottom of the screen), on maps, go down with the arrow until you find the map version (last is north america 2008a)
Garmin: press tools,settings, map and map info(last is north america 2010)
Navigon: select "options" and product informations
Tomtom : click up to signal satellite, after click on the version.(example, Map USA_and_Canada,
Magellan: Select "User Options"; Scroll down and select "Map Options"; Your map version is on the line titled "Detailed Map NavStreets Version"