I just learned something today that should be noted for Garmin POI files. A lot of European downloads were not working for me, and I posted the problem in the Garmin forum. The app developer said that the data has to be formatted using UTF-8 only. The POIs won't import using any other character set, depending on the model, etc. So, open it up in a good text editor and reformat using UTF-8 and you're golden.
HTH for those that are still stumped. I was trying to bring these into Garmin BaseCamp and most of them wouldn't go through, as they were formatted using Central European ISO-Latin 2. I am not sure if GPS Data Team outputs using that format, or the data is entered using that format...I'm not sure of the engine...but it has to be changed.