An interesting difference between classic and new style objects

[Oren Tirosh]

Actually, the title of this thread is misleading.  I don't mind too much if 
there are certain differences between classic and new style objects. The 
problem is that Python code and builtin functions don't have the same view 
of a new style object.  A builtin function sees only the methods the object 
had at the time it was instantiated while Python code can see methods that 
have been added or modified by assignment.  

Is the modification of an object's methods an officially supported language
feature or is this considered messing with internal stuff?

	Oren