AttributeError when opening annotate on a added, uncommitted file from TreeWidget

[Mfoniso Ossom]

bzr: ERROR: exceptions.AttributeError: 'NoneType' object has no attribute 'lock_read'

Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/qbzr/lib/trace.py", line 291, in reports_exception_decorate
    return f(*args, **kargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/qbzr/lib/annotate.py", line 307, in initial_load
    self.branch.lock_read()
AttributeError: 'NoneType' object has no attribute 'lock_read'

bzr 2.1.1 on python 2.6.4 (linux2)
arguments: ['/usr/bin/bzr', 'qcommit', '--ui-mode']
encoding: 'UTF-8', fsenc: 'UTF-8', lang: 'en_ZA.UTF-8'
plugins:
  bzrtools /usr/lib/python2.6/dist-packages/bzrlib/plugins/bzrtools [2.1.0]
  explorer /usr/lib/python2.6/dist-packages/bzrlib/plugins/explorer [1.0.0]
  extmerge /home/mfoniso/.bazaar/plugins/extmerge [unknown]
  launchpad /usr/lib/python2.6/dist-packages/bzrlib/plugins/launchpad [2.1.1]
  netrc_credential_store /usr/lib/python2.6/dist-packages/bzrlib/plugins/netrc_credential_store [2.1.1]
  news_merge /usr/lib/python2.6/dist-packages/bzrlib/plugins/news_merge [2.1.1]
  qbzr /usr/lib/python2.6/dist-packages/bzrlib/plugins/qbzr [0.18.4]

[Gary van der Merwe (garyvdm)]

Steps to reproduce:

bzr init test604080
cd test604080
echo foo > bar
bzr qcommit

Right click on bar, Add
Right click on bar, Annotate

If you close commit, and open again, then it works, so something must be going wrong when the treewidget refreshes after the file is added.