bzr merge using merge-directive result with error

The following trace it triggered after executing bzr merge <merge directive>.
Merging from the branch that was used to create the directive pass successfully.
Additionally, after merging from the the actual branch and reverting,
bzr merge <merge directive> pass without triggering the trace but with different
result (compared with merge from the actual branch).

bzr: ERROR: exceptions.IndexError: list index out of range

Traceback (most recent call last):
  File "/usr/lib64/python2.6/site-packages/bzrlib/commands.py", line 853, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/usr/lib64/python2.6/site-packages/bzrlib/commands.py", line 1055, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib64/python2.6/site-packages/bzrlib/commands.py", line 661, in run_argv_aliases
    return self.run_direct(**all_cmd_args)
  File "/usr/lib64/python2.6/site-packages/bzrlib/commands.py", line 665, in run_direct
    return self._operation.run_simple(*args, **kwargs)
  File "/usr/lib64/python2.6/site-packages/bzrlib/cleanup.py", line 122, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/usr/lib64/python2.6/site-packages/bzrlib/cleanup.py", line 156, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/usr/lib64/python2.6/site-packages/bzrlib/builtins.py", line 3783, in run
    mergeable, pb)
  File "/usr/lib64/python2.6/site-packages/bzrlib/merge.py", line 321, in from_mergeable
    mergeable.install_revisions(tree.branch.repository)
  File "/usr/lib64/python2.6/site-packages/bzrlib/merge_directive.py", line 240, in install_revisions
    info.install_revisions(target_repo, stream_input=False)
  File "/usr/lib64/python2.6/site-packages/bzrlib/bundle/serializer/v4.py", line 471, in install_revisions
    return ri.install()
  File "/usr/lib64/python2.6/site-packages/bzrlib/bundle/serializer/v4.py", line 539, in install
    result = self._install_in_write_group()
  File "/usr/lib64/python2.6/site-packages/bzrlib/bundle/serializer/v4.py", line 569, in _install_in_write_group
    self._install_inventory_records(pending_inventory_records)
  File "/usr/lib64/python2.6/site-packages/bzrlib/bundle/serializer/v4.py", line 690, in _install_inventory_records
    ).to_lines(p_texts)
  File "/usr/lib64/python2.6/site-packages/bzrlib/multiparent.py", line 167, in to_lines
    return mpvf.get_line_list(['a'])[0]
  File "/usr/lib64/python2.6/site-packages/bzrlib/multiparent.py", line 502, in get_line_list
    return [self.cache_version(v) for v in version_ids]
  File "/usr/lib64/python2.6/site-packages/bzrlib/multiparent.py", line 512, in cache_version
    reconstructor.reconstruct_version(lines, version_id)
  File "/usr/lib64/python2.6/site-packages/bzrlib/multiparent.py", line 661, in reconstruct_version
    return self._reconstruct(lines, version_id, 0, length)
  File "/usr/lib64/python2.6/site-packages/bzrlib/multiparent.py", line 654, in _reconstruct
    new_version_id = self.parents[req_version_id][parent]
IndexError: list index out of range

bzr 2.1.2 on python 2.6.4 (Linux-2.6.34.7-56.fc13.x86_64-x86_64-with-fedora-13-Goddard)
arguments: ['/usr/bin/bzr', 'merge', '/tmp/bzr.out']
encoding: 'UTF-8', fsenc: 'UTF-8', lang: 'en_US.UTF-8'
plugins:
  explorer /usr/lib/python2.6/site-packages/bzrlib/plugins/explorer [1.0.2]
  launchpad /usr/lib64/python2.6/site-packages/bzrlib/plugins/launchpad [2.1.2]
  netrc_credential_store /usr/lib64/python2.6/site-packages/bzrlib/plugins/netrc_credential_store [2.1.2]
  news_merge /usr/lib64/python2.6/site-packages/bzrlib/plugins/news_merge [2.1.2]
  qbzr /usr/lib/python2.6/site-packages/bzrlib/plugins/qbzr [0.19.2]

*** 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
    including this traceback and a description of the problem.