The following code is not working as expected:
import weakref
class cls1:
	def giveTo( self, to ):
		to.take( self.bla )
	def bla(self ):
		pass
		
class cls2:
	def take( self, what ):
		self.ref = weakref.ref(what)
		
c1 = cls1()
c2 = cls2()
c1.giveTo( c2 )
print c1.bla
print c2.ref

It prints out:
<bound method cls1.bla of <__main__.cls1 instance at 0x00CA9E18>>
<weakref at 00CAF180; dead>

Why is the weakref pointing to a dead object, when it's still alive?