I was trying to upgrade to 6.60 OFW (for 6.60 pro c2) from 5.00 m33-4. But i get error "The system configuration of this PSP system does not appear to be correct. The update cannot be started. Contact technical support for assistance. (DRNFFFFFFC4)" I searched the error DRNFFFFFFC4 and it has something to do with key 0x6 missing. How do I add it back?