I am no expert and can only give 2 ideas that both could be wrong.
1. Somehow the Polaris keeps looking for a particular SDcard that is linked to the device.
2. the maplaunch.ini file holds the wrong path (primo2 or Primo2A??), did you misstype?

[GPS]
path = Primo2A\Primo2.exe;
bmpiconpath = Primo2\ui_igo9\800_480\loading.bmp;
showname = GRK;