Cannot pull the branch

Can you advice with such problem? It worked correctly before a lot of times. Now I repeat it for 3 days with this result.
It goes with fetching revisions: Inserting streams and suddenly finish.

gg@gg-laptop:~/openerp/server$ bzr pull
Using saved parent location: http://bazaar.launchpad.net/~openerp/openobject-server/5.0/
bzr: failed to report crash using apport:
     IOError(13, 'Permission denied')
bzr: ERROR: bzrlib.errors.BzrCheckError: Internal check failed: Cannot add revision(s) to repository: missing referenced chk root keys: [StaticTuple('sha1:3608184c2cd5014e07bd789396193a1ad5fc3c16',)]

Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 853, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 1055, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 661, in run_argv_aliases
    return self.run_direct(**all_cmd_args)
  File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 665, in run_direct
    return self._operation.run_simple(*args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/cleanup.py", line 122, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/cleanup.py", line 156, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/builtins.py", line 1013, in run
    possible_transports=possible_transports, local=local)
  File "/usr/lib/python2.6/dist-packages/bzrlib/decorators.py", line 194, in write_locked
    result = unbound(self, *args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/workingtree.py", line 1614, in pull
    local=local)
  File "/usr/lib/python2.6/dist-packages/bzrlib/decorators.py", line 194, in write_locked
    result = unbound(self, *args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/branch.py", line 962, in pull
    possible_transports=possible_transports, *args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/branch.py", line 3200, in pull
    _override_hook_target=_override_hook_target)
  File "/usr/lib/python2.6/dist-packages/bzrlib/branch.py", line 3077, in pull
    overwrite=overwrite, graph=graph)
  File "/usr/lib/python2.6/dist-packages/bzrlib/decorators.py", line 194, in write_locked
    result = unbound(self, *args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/branch.py", line 910, in update_revisions
    overwrite, graph)
  File "/usr/lib/python2.6/dist-packages/bzrlib/branch.py", line 3020, in update_revisions
    self.target.fetch(self.source, stop_revision)
  File "/usr/lib/python2.6/dist-packages/bzrlib/decorators.py", line 194, in write_locked
    result = unbound(self, *args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/branch.py", line 593, in fetch
    pb=pb)
  File "/usr/lib/python2.6/dist-packages/bzrlib/repository.py", line 1704, in fetch
    find_ghosts=find_ghosts, fetch_spec=fetch_spec)
  File "/usr/lib/python2.6/dist-packages/bzrlib/decorators.py", line 194, in write_locked
    result = unbound(self, *args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/repository.py", line 3432, in fetch
    pb=pb, find_ghosts=find_ghosts)
  File "/usr/lib/python2.6/dist-packages/bzrlib/fetch.py", line 83, in __init__
    self.__fetch()
  File "/usr/lib/python2.6/dist-packages/bzrlib/fetch.py", line 109, in __fetch
    self._fetch_everything_for_search(search)
  File "/usr/lib/python2.6/dist-packages/bzrlib/fetch.py", line 137, in _fetch_everything_for_search
    stream, from_format, [])
  File "/usr/lib/python2.6/dist-packages/bzrlib/repository.py", line 4274, in insert_stream
    return self._locked_insert_stream(stream, src_format, is_resume)
  File "/usr/lib/python2.6/dist-packages/bzrlib/repository.py", line 4377, in _locked_insert_stream
    hint = self.target_repo.commit_write_group()
  File "/usr/lib/python2.6/dist-packages/bzrlib/repository.py", line 1563, in commit_write_group
    result = self._commit_write_group()
  File "/usr/lib/python2.6/dist-packages/bzrlib/repofmt/pack_repo.py", line 2314, in _commit_write_group
    hint = self._pack_collection._commit_write_group()
  File "/usr/lib/python2.6/dist-packages/bzrlib/repofmt/pack_repo.py", line 2152, in _commit_write_group
    "Cannot add revision(s) to repository: " + problems_summary)
BzrCheckError: Internal check failed: Cannot add revision(s) to repository: missing referenced chk root keys: [StaticTuple('sha1:3608184c2cd5014e07bd789396193a1ad5fc3c16',)]

bzr 2.1.0 on python 2.6.2 (Linux-2.6.28-18-generic-i686-with-Ubuntu-9.04-jaunty)
arguments: ['/usr/bin/bzr', 'pull']
encoding: 'UTF-8', fsenc: 'UTF-8', lang: 'pl_PL.UTF-8'
plugins:
  bzrtools /usr/lib/python2.6/dist-packages/bzrlib/plugins/bzrtools [2.1.0]
  launchpad /usr/lib/python2.6/dist-packages/bzrlib/plugins/launchpad [2.1.0]
  netrc_credential_store /usr/lib/python2.6/dist-packages/bzrlib/plugins/netrc_credential_store [2.1.0]
  news_merge /usr/lib/python2.6/dist-packages/bzrlib/plugins/news_merge [2.1.0]

*** 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.
gg@gg-laptop:~/openerp/server$