Maemo Mapper doesn't support the wpt tag. It's a long story, but it doesn't really fit with Maemo Mapper's track data structures. (Why are the waypoints separate from track points? How am I supposed to correlate the two?) ... I've been meaning to add more robust support for GPX to Maemo Mapper, including support of the wpt tag, but it might break backward compatibility, so I'm saving it for Maemo Mapper v2.0.