Satnavs often lose cover in cities
As I found out when I drove my van to Zurich to collect all the stuff from my flat. After 8 years of living and working there, I had managed to collect more than I could take back on the plane, so I drove over there to fetch it.
Problem was, I'd never actually driven a car in Zurich and was relying on sat nav to find my way through the one-way systems. As soon as I passed under the overhead lines for the trams, satnav went completely mental and was no help at all. took me about half an hour of dicking about to find my way to the apartment.