Problem solved! It seems that some Microsoft security update was the culprit. We added a rule to the windows Firewall to allow Garmin Express, and it is now working perfectly! His Nuvi was subsequently updated to the latest map. I must say calling Garmin was a kind of useless exercise! All they recommended was using another USB cable. This after we told them that we do see the Nuvi in Windows Explorer, as well as with Basecamp and Mapsource.