Earlier in the year I debranded my Vodafone N95-8GB to 0549487 - EURO1. This allowed me to upgrade the firmware and get better GPS performance (but still poor). I just ran NSU and it found version 20 for the phone so I upgraded it. After restarting it had the Vodafone customisation (splash screen and shortcuts). Product code is now 0557135. So, does NSU detect the phone variant by some means other than product code now, and reset the product code accordingly?
PS GPS performance is brilliant now; locks in under 10 seconds!