I have the exact same problem with a 4310max. Sometimes Navigon fresh detects my device, but then I am unable to log on to the server in order to register the product.
Funny thing is that windows explorer is detecting the device as an external drive. I can browes through the files on the gps, but Navigon Fresh keeps saying: Navigon fresh could not detect.....
Any idea? Tried to reset the device too, restarting windows yadiyadiyadi. Nothing works.
Getting really pissed off here. Maybe better to copy maps on paper from the yellow pages.