gtk+ tree oddness

#!/usr/bin/python

# 1. Launch gtk3-demo and this listener
# 2. Down Arrow several times in the tree on the left
# 3. Up Arrow several times in the tree on the left
# 4. Down Arrow several times in the tree on the left
#
# Results: As soon as step 3 gets performed, items claim to not be selected

import pyatspi

def listener(e):
    newDescendant = e.any_data
    state = newDescendant.getState()
    print "new descendant: %s is selected: %s" % \
        (newDescendant.name, bool(state.contains(pyatspi.STATE_SELECTED)))

pyatspi.Registry.registerEventListener(listener, "object:active-descendant-changed")
pyatspi.Registry.start()