Nokia designed Ovi Maps with the "always connected" philosophy in mind.

As such, it tends to have trouble with the GPS if a connection isn't locked quickly (about 30s ?). It also needs to be online to search for points of interest, and possibly even driving directions.

Apparently Nokia did not take into account the fact that people may not have data coverage available (outside service area, outside home country, no data subscription) and still want / need to use the Maps feature.