inspect.isclass() can return True for instances of classes   
which define a __getattr__ method.  For example:   
   
>>> class Namespace(unicode):   
...    def __getattr__(self, attr):   
...       return '<%s>' % (self + attr)   
...   
>>> inspect.isclass(Namespace('foo'))   
True   
   
Changing inspect.isclass() to:   
  return isinstance(object, (types.ClassType, type))   
solves this issue.   
   
The check for __bases__ is no longer need due to   
type/class unification.   

Finally fixed in r68676.