bzr status raise 'NoneType' object is unsubscriptable error

bzr: ERROR: exceptions.TypeError: 'NoneType' object is unsubscriptable

Traceback (most recent call last):
  File "/opt/local/lib/python2.5/site-packages/bzrlib/commands.py", line 806, in run_bzr_catch_errors
    return run_bzr(argv)
  File "/opt/local/lib/python2.5/site-packages/bzrlib/commands.py", line 762, in run_bzr
    ret = run(*run_argv)
  File "/opt/local/lib/python2.5/site-packages/bzrlib/commands.py", line 492, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/opt/local/lib/python2.5/site-packages/bzrlib/commands.py", line 772, in ignore_pipe
    result = func(*args, **kwargs)
  File "/Users/cskinfill/.bazaar/plugins/bzr_xmloutput_0_4/__init__.py", line 78, in run
    revision=revision, short=short, versioned=versioned)
  File "/opt/local/lib/python2.5/site-packages/bzrlib/commands.py", line 772, in ignore_pipe
    result = func(*args, **kwargs)
  File "/opt/local/lib/python2.5/site-packages/bzrlib/builtins.py", line 189, in run
    to_file=self.outf, short=short, versioned=versioned)
  File "/opt/local/lib/python2.5/site-packages/bzrlib/status.py", line 114, in show_tree_status
    want_unversioned=want_unversioned)
  File "/opt/local/lib/python2.5/site-packages/bzrlib/tree.py", line 93, in changes_from
    want_unversioned=want_unversioned,
  File "/opt/local/lib/python2.5/site-packages/bzrlib/decorators.py", line 127, in read_locked
    return unbound(self, *args, **kwargs)
  File "/opt/local/lib/python2.5/site-packages/bzrlib/tree.py", line 707, in compare
    want_unversioned=want_unversioned)
  File "/opt/local/lib/python2.5/site-packages/bzrlib/delta.py", line 217, in _compare_trees
    want_unversioned=want_unversioned):
  File "/opt/local/lib/python2.5/site-packages/bzrlib/workingtree_4.py", line 2360, in _iter_changes
    result = _process_entry(current_entry, current_path_info)
  File "/opt/local/lib/python2.5/site-packages/bzrlib/workingtree_4.py", line 1954, in _process_entry
    source_details = old_entry[1][source_index]
TypeError: 'NoneType' object is unsubscriptable

bzr 1.1.0 on python 2.5.1.final.0 (darwin)
arguments: ['/opt/local/bin/bzr', 'stat']
encoding: 'UTF-8', fsenc: 'utf-8', lang: 'en_US.UTF-8'
plugins:
  bzr_xmloutput_0_4 /Users/cskinfill/.bazaar/plugins/bzr_xmloutput_0_4 [0.4.0]
  launchpad /opt/local/lib/python2.5/site-packages/bzrlib/plugins/launchpad [unknown]
  multiparent /opt/local/lib/python2.5/site-packages/bzrlib/plugins/multiparent.pyc [unknown]
*** Bazaar has encountered an internal error.
    Please report a bug at https://bugs.launchpad.net/bzr/+filebug
    including this traceback, and a description of what you
    were doing when the error occurred.