usually GPS POI Source File Format is CSV file format.
The CSV format is: Longitude,latitude,”comment”
This is an example (LPG station POI)
3.39970, 49.03697, “02 – CHATEAU THIERRY – Intermarché – 16 avenue de l’ Europe”
use the windows “notepad” or Wordpad to open your csv file.
You should have 3 columns as descibed above.
Then you can change the content of the file with “search & replace” for instance.
If your file really content only 47 lines and POILoader is stating 511, this means that your are loading other POI’s from an other CSV fle …