Wow that fixed it. You are a Python Ninja :-) I would sure like to know what the mechanism was that caused driver_args to bleed from SQLLite to the other adapters even though it is defaulted it to an empty dict on the class initializer. I also printed driver_args as the first line of code in DAL.__init__() and it had the value left over from SQLLite so how driver_args or {} produces {} when there is a value in driver_args.
But you are very busy so if you don't have time no problem.