Why downgrade? You need to upgrade to fw 030! After the upgrade, you need to unlock your unit with unlock DVD. Only than the system will accept new maps. But unfortunately it's also very difficult to burn a good quality copy of the map DVD. Burning speed must be max 4x, so the lower, the better. You must find an old burner. LG burners are most compatible for this system. I'm using my external USB writer PLEXTOR PX-608U and also internal LG GH22NS4. Both capable making working copies.