Find the map version in your gps

Sony: 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, v715.1712)

Magellan: Select "User Options"; Scroll down and select "Map Options"; Your map version is on the line titled "Detailed Map NavStreets Version"