Well something interesting for you. I have just had my NG4 replaced under warranty (this is my 3rd unit in 12 months), as it decided to start randomly rebooting continuously.
My previous unit was originally running 2010/2011 maps and the 26.04 firmware, I updated to the 32.05 via the official CD and updated the maps to 2011/2012 via the official DVD's. After this the date of the speed camera database file would never update past December 2011 (although it seems the actual database was updating).
Well my new unit, came from the factory with 32.05 and 2011/2012 maps but obviously no speed cameras. So I loaded up the database and guess what....the date is correct and I have installed the March database and then the April one and the date changed.
So I can only assume the 'bug' is something to do with the update procedure, rather than the actual firmware build.