PyThreadState_Swap difference in 2.3.2?

[Paul Miller]

>It seems to me that GenericGetAttr() should not assume mro to be
>initialized. I haven't come across any sample custom types that initialize
>it, and for whatever reason, it is not getting set up automatically.

I traced through my initialization code, where I am "readying" my custom
types, and it is failing in the mro_implementation() function in
typeobject.c. For whatever reason, the PySequence_List() call in this
function is failing. 

I have no clue why at this point.