Uninstall package I sent U the link. Download navifirm
Symbian Toys - Software NaviFirm+ to dowload the firmware of your Symbian smartphone choose C6-00 rm-612 in this soft and download product code U need. Files U downloaded by navifirm place into C:\Program files\Nokia\Phoenix\Products\RM-612 then try flash phone using Phoenix.
B.R.
ProcyOne
BTW in navifirm i see highest fw but not all pcodes.