backtraces if a repository is branched simultaneously

trying to run this branch simultaneously (in different windows) results in the second backtracing like this:

11:17:42 kgoetz@epicfail: ~ $ bzr branch svn://svn.debian.org/d-i/trunk/packages/live-installer debian-live-installer
bzr: ERROR: sqlite3.OperationalError: database is locked

Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 842, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 1037, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 654, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.5/site-packages/bzrlib/builtins.py", line 1215, in run
    revision_id = br_from.last_revision()
  File "/home/kgoetz/.bazaar/plugins/svn/branch.py", line 539, in last_revision
    last_revmeta, mapping = self.last_revmeta()
  File "/home/kgoetz/.bazaar/plugins/svn/branch.py", line 293, in last_revmeta
    for revmeta, mapping in self._revision_meta_history():
  File "/home/kgoetz/.bazaar/plugins/svn/util.py", line 142, in next
    return self._next()
  File "/home/kgoetz/.bazaar/plugins/svn/util.py", line 124, in _next
    ret = self._iterator.next()
  File "/home/kgoetz/.bazaar/plugins/svn/repository.py", line 811, in _iter_reverse_revmeta_mapping_history
    (mapping, lhs_mapping) = revmeta.get_appropriate_mappings(mapping)
  File "/home/kgoetz/.bazaar/plugins/svn/revmeta.py", line 392, in get_appropriate_mappings
    original = self.get_original_mapping()
  File "/home/kgoetz/.bazaar/plugins/svn/revmeta.py", line 875, in get_original_mapping
    self._original_mapping)
  File "/home/kgoetz/.bazaar/plugins/svn/cache/sqlitecache.py", line 251, in set_original_mapping
    self.cachedb.execute("insert into original_mapping (path, revnum, original_mapping) values (?, ?, ?)", (foreign_revid[1], foreign_revid[2], orig_mapping_name))
OperationalError: database is locked