Embedding Python - Deleting a class instance

[Bue Krogh Vedel-Larsen]

How do I delete a class instance created using PyInstance_New? I've tried 
calling Py_CLEAR on the instance, but __del__ isn't called. I've also tried 
calling PyObject_Del, but this gives an access violation in 
_PyObject_DebugDumpAddress so I guess that ain't a good idea :)

I've noticed that the PyObject returned by PyInstance_New has refcount = 2, 
does this have any significance?