after changing the product code using Nemis, here is what you need to do.
1)Install Nokia PC suite (if already done skip the steps)
2)Install Nokia software updater (NSU)
3)Connect phone with cable to pc and choose "pc suite mode"
4)Open NSU and update phone.
5)After done, do a reset, press: *#7370#
So I think you changed the product code, but didn't update with NSU.