IndexError: in dirstate update_minimal

Binary package hint: bzr

Here's the bzr's output in the terminal:

$ bzr move admin/inc/html admin/xhtml
bzr: ERROR: exceptions.IndexError: list index out of range

*** Bazaar has encountered an internal error. This probably indicates a
    bug in Bazaar. You can help us fix it by filing a bug report at
        https://bugs.launchpad.net/bzr/+filebug
    attaching the crash file
        /home/nom/.cache/crash/bzr-20091206010435-1428.crash
    and including a description of the problem.

    The crash file is plain text and you can inspect or edit it to remove
    private information.
$

I'll attach the crash file.

 Traceback (most recent call last):
   File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 842, in exception_to_return_code
     return the_callable(*args, **kwargs)
   File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 1037, in run_bzr
     ret = run(*run_argv)
   File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 654, in run_argv_aliases
     return self.run(**all_cmd_args)
   File "/usr/lib/python2.6/dist-packages/bzrlib/builtins.py", line 808, in run
     self._run(tree, names_list, rel_names, after)
   File "/usr/lib/python2.6/dist-packages/bzrlib/builtins.py", line 901, in _run
     tree.rename_one(src, dest, after=after)
   File "/usr/lib/python2.6/dist-packages/bzrlib/mutabletree.py", line 52, in tree_write_locked
     return unbound(self, *args, **kwargs)
   File "/usr/lib/python2.6/dist-packages/bzrlib/workingtree_4.py", line 1245, in rename_one
     WorkingTree.rename_one(self, from_rel, to_rel, after)
   File "/usr/lib/python2.6/dist-packages/bzrlib/mutabletree.py", line 52, in tree_write_locked
     return unbound(self, *args, **kwargs)
   File "/usr/lib/python2.6/dist-packages/bzrlib/workingtree.py", line 1535, in rename_one
     self._write_inventory(inv)
   File "/usr/lib/python2.6/dist-packages/bzrlib/mutabletree.py", line 52, in tree_write_locked
     return unbound(self, *args, **kwargs)
   File "/usr/lib/python2.6/dist-packages/bzrlib/workingtree_4.py", line 1270, in _write_inventory
     self.current_dirstate().set_state_from_inventory(inv)
   File "/usr/lib/python2.6/dist-packages/bzrlib/dirstate.py", line 2629, in set_state_from_inventory
     fullscan=True)
   File "/usr/lib/python2.6/dist-packages/bzrlib/dirstate.py", line 2797, in update_minimal
     other_key = list(existing_keys)[0]
 IndexError: list index out of range