I have what appears to be the same blocking problem:

joey@c14n:~/helpwikitheme$ bzr commit -m"reordered to match production" > /home/joey/bzrcommiterror.txt
Committing to: /home/joey/helpwikitheme/
modified htdocs/lp1_0theme
added htdocs/lphelpwiki
bzr: ERROR: exceptions.AttributeError: children

Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 834, in run_bzr_catch_errors
    return run_bzr(argv)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 790, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 492, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.5/site-packages/bzrlib/builtins.py", line 2329, in run
    author=author)
  File "/usr/lib/python2.5/site-packages/bzrlib/decorators.py", line 165, in write_locked
    return unbound(self, *args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/workingtree_4.py", line 246, in commit
    result = WorkingTree3.commit(self, message, revprops, *args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/decorators.py", line 165, in write_locked
    return unbound(self, *args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/mutabletree.py", line 187, in commit
    revprops=revprops, *args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/commit.py", line 355, in commit
    self._update_builder_with_changes()
  File "/usr/lib/python2.5/site-packages/bzrlib/commit.py", line 656, in _update_builder_with_changes
    self._populate_from_inventory(specific_files)
  File "/usr/lib/python2.5/site-packages/bzrlib/commit.py", line 784, in _populate_from_inventory
    content_summary)
  File "/usr/lib/python2.5/site-packages/bzrlib/commit.py", line 826, in _record_entry
    self.parent_invs, path, self.work_tree, content_summary)
  File "/usr/lib/python2.5/site-packages/bzrlib/repository.py", line 266, in record_entry_contents
    self.new_inventory.add(ie)
  File "/usr/lib/python2.5/site-packages/bzrlib/inventory.py", line 1185, in add
    if entry.name in parent.children:
AttributeError: children

bzr 1.2.0 on python 2.5.1.final.0 (linux2)
arguments: ['/usr/bin/bzr', 'commit', '-mreordered to match production']
encoding: 'UTF-8', fsenc: 'UTF-8', lang: 'en_US.UTF-8'
plugins:
  bzr_branchfeed       /home/joey/.bazaar/plugins/bzr_branchfeed [unknown]
  bzrtools             /usr/lib/python2.5/site-packages/bzrlib/plugins/bzrtools [1.2.0]
  gnulog               /home/joey/.bazaar/plugins/gnulog.py [unknown]
  gtk                  /usr/lib/python2.5/site-packages/bzrlib/plugins/gtk [0.93.0]
  htmllog              /home/joey/.bazaar/plugins/htmllog [unknown]
  launchpad            /usr/lib/python2.5/site-packages/bzrlib/plugins/launchpad [unknown]
  lpreview             /home/joey/.bazaar/plugins/lpreview [unknown]
  pqm                  /usr/lib/python2.5/site-packages/bzrlib/plugins/pqm [0.92.0]
  stats                /home/joey/.bazaar/plugins/stats [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.
joey@c14n:~/helpwikitheme$