I'd like to use my Garmin GPSmap 296 with SD. The route export and track log import always work as expected with either Auto or USB as device connectivity.

After buying the navigation upgrade, on GPS navigation options I don't get USB in the list of ports as expected. This is the same for Windows XP and 7.

Indeed, the documentation (GPS Navigation Facilities) only mentions the port and baud parameters, so maybe a USB connection is not an option although this is not mentioned.

So is USB supported for import/export but not for navigation, or is there a step I have missed?