I had db commander open to the players.dbf file of my dynasty, forgot about it, and went to play said dynasty. because NBA Live 06 couldnt access the players.dbf that I had open, it loaded the default one.
Indeed. Problems arise when you're editing the databases with the game open and forget to shut down DB Commander (or just close the database while leaving DB Commander open, if you need to switch back and forth for whatever reason). Always make sure you don't have a database open with an external program when playing a Dynasty game or loading/saving a roster.
And as always, keep a backup handy when you're playing around with the databases.