I usually have my eTrex Legend Units>Position Format set to 'British Grid' and Map Datum 'Ord Srvy GB'. Viewing any .gpx file copied from its Data Card to my PC, the coordinates are present in the 'Position' column when viewed in BaseCamp.
I holidayed in Greece recently. I reset the Units>Position Format (I cannot remember which I chose: decimal degrees, degrees/decimal minutes or degrees/minutes/decimal seconds, but it was one of those) and Map Datum 'WGS 84'. Now, when I view the Data Card's tracklog copied to the PC, the 'Position' column is empty. The same applies to the waypoints, although I can view their locations on the device, itself. Can anyone tell me why?