Debug builtin subclasses

Hi,
there is a issue watching a object subclassed from a built in (e.g. dict).

class Prova(dict):
    def __init__(self):
        dict.__init__(self)
        self.pippo="PIPPO"
pippo=Prova()

watching the variable pippo i should view pluto.pippo. This is what i get:






pluto.pippo exist but i can't see it in the debugger...