Is it true that stamp_inserted and stamp_updated don't get touched unless sql_history and sql_history_roundoff are also set? If so, when did this change?
I was running 0.7.4 for a while and I didn't have these set, recently I upgraded and have found data missing. I'm a bit surprised that this might be the cause, though the documentation in CONFIG-KEYS leads me to believe this is the case... also I wonder what the pmacctd processes might have done when trying to write NULL data to a NOT NULL column in the database (namely, stamp_inserted).