Logged In: YES 
user_id=4771

It is not the type object that is cleared, it is the global
names of the module.  They are replaced with None when the
interpreter shuts down, which is why the expression
'Shape.refcount' find None under the name 'Shape'.  It's an
obscure leftover for historical reasons.  I'm not sure why
the problem somes bites and sometimes not.  A workaround is
to avoid reading globals from __del__() methods; e.g. use
self.__class__.refcount instead of Shape.refcount...

(This of course doesn't excuse the fact that this is a
long-standing bug.)