NoSuchId traceback when branching a svn repository

When branching the scipy trunk repository, I get an traceback at revision 1468:

Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 802, in run_bzr_catch_errors
    return run_bzr(argv)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 758, 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 646, in run
    possible_transports=possible_transports)
  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.py", line 1539, in pull
    possible_transports=possible_transports)
  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/branch.py", line 1726, in pull
    run_hooks=run_hooks)
  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/branch.py", line 1525, in pull
    self.update_revisions(source, stop_revision, overwrite=overwrite)
  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/branch.py", line 1477, in update_revisions
    self.fetch(other, stop_revision)
  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/branch.py", line 286, in fetch
    pb=nested_pb)
  File "/usr/lib/python2.5/site-packages/bzrlib/repository.py", line 873, in fetch
    return inter.fetch(revision_id=revision_id, pb=pb, find_ghosts=find_ghosts)
  File "/home/david/.bazaar/plugins/svn/fetch.py", line 693, in fetch
    self._fetch_switch(needed, pb, lhs_parent)
  File "/home/david/.bazaar/plugins/svn/fetch.py", line 650, in _fetch_switch
    reporter.finish_report(pool)
  File "/home/david/.bazaar/plugins/svn/errors.py", line 97, in convert
    return unbound(*args, **kwargs)
  File "/home/david/.bazaar/plugins/svn/transport.py", line 271, in finish_report
    self._baton, pool)
  File "/var/lib/python-support/python2.5/libsvn/ra.py", line 740, in svn_ra_reporter2_invoke_finish_report
    return apply(_ra.svn_ra_reporter2_invoke_finish_report, args)
  File "/home/david/.bazaar/plugins/svn/fetch.py", line 337, in open_file
    base_file_id = self._get_old_id(parent_id, path)
  File "/home/david/.bazaar/plugins/svn/fetch.py", line 175, in _get_old_id
    return self.old_inventory[parent_id].children[urlutils.basename(old_path)].file_id
  File "/usr/lib/python2.5/site-packages/bzrlib/inventory.py", line 1145, in __getitem__
    raise errors.NoSuchId(self, file_id)

The repository is http//svn.scipy.org/svn/scipy (trunk only). The problem happens at revision 1468.

Thank you,

David