Stuart, this is a different issue than what he is referring to. The Monterra is a little different than most other Garmin devices in that it operates on the Android platform. If you are looking to update the device you should be able to do so over the air. https://support.garmin.com/support/searchSupport/case.faces?caseId={6a6d9e20-3671-11e3-f27b-000000000000} . If you are looking to buy maps we suggest that you consider shopping for downloadable maps. If you have purchased a City Navigator DVD and are looking to update you will have to do so from a PC at this time.
