bzr: ERROR: exceptions.SystemError: Negative size passed to PyString_FromStringAndSize

After doing "bzr commit -m ..." we got a Segmentation Fault, then I tried "bzr check" and got this error:

$ bzr check
checked branch file:///var/www/our_project/ format Bazaar Branch Format 6 (bzr 0.15)
checked repository <bzrlib.transport.local.LocalTransport url=file:///var/www/our_project/> format <RepositoryFormatKnitPack1>
   504 revisions
  1960 file-ids
  5275 unique file texts
328137 repeated file texts
     0 unreferenced text versions
bzr: ERROR: exceptions.SystemError: Negative size passed to PyString_FromStringAndSize

Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 846, in run_bzr_catch_errors
    return run_bzr(argv)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 797, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 499, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.5/site-packages/bzrlib/builtins.py", line 2436, in run
    if len(list(repo_basis.iter_changes(tree_basis))):
  File "/usr/lib/python2.5/site-packages/bzrlib/tree.py", line 784, in iter_changes
    from_entries_by_dir = list(self.source.inventory.iter_entries_by_dir(
  File "/usr/lib/python2.5/site-packages/bzrlib/workingtree_4.py", line 1623, in _get_inventory
    self._generate_inventory()
  File "/usr/lib/python2.5/site-packages/bzrlib/workingtree_4.py", line 1479, in _generate_inventory
    self._dirstate._read_dirblocks_if_needed()
  File "/usr/lib/python2.5/site-packages/bzrlib/dirstate.py", line 1963, in _read_dirblocks_if_needed
    _read_dirblocks(self)
  File "_dirstate_helpers_c.pyx", line 694, in _dirstate_helpers_c._read_dirblocks_c
  File "_dirstate_helpers_c.pyx", line 661, in _dirstate_helpers_c.Reader._parse_dirblocks
  File "_dirstate_helpers_c.pyx", line 608, in _dirstate_helpers_c.Reader._get_entry
  File "_dirstate_helpers_c.pyx", line 502, in _dirstate_helpers_c.Reader.get_next_str
SystemError: Negative size passed to PyString_FromStringAndSize

bzr 1.5 on python 2.5.5 (linux2)
arguments: ['/usr/bin/bzr', 'check']
encoding: 'UTF-8', fsenc: 'UTF-8', lang: 'en_US.UTF-8'
plugins:
  bzrtools /usr/lib/python2.5/site-packages/bzrlib/plugins/bzrtools [1.5.0]
  launchpad /usr/lib/python2.5/site-packages/bzrlib/plugins/launchpad [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.

Thanks in advance.