ValueError: failed to deserialize tag dictionary

With a recent installation of bzr (Windows 7), having done a checkout from launchpad and one commit, a subsequent commit returned the following error. bzr status claims that the working tree is out of date, but any bzr update also returns this error.

bzr: ERROR: exceptions.ValueError: failed to deserialize tag dictionary 'd12:hyp
edyn2.1.648:<email address hidden>:hypedyn2.1.748:al
<email address hidden>:hypedyn2.2.048:<email address hidden>
-20130607170011-9qblo8xrpu5b80yn12:hypedyn2.2a148:<email address hidden>
9-ugc7d4dghi4nzvue12:hypedyn2.2a248:<email address hidden>
0tmj12:hypedyn2.2a348:<email address hidden>:hypedyn
2.2a548:<email address hidden>:hypedyn2.2b148:alexm@
nus.edu.sg-20120814154415-lky5is9h2myvrytd12:hypedyn2.2b348:<email address hidden>
21001013143-1415axl27422noho12:hypedyn2.2b548:<email address hidden>
28glsa2r9gbm7911:hypedyn2.3a248:<email address hidden>
e': stream underflow

Traceback (most recent call last):
  File "bzrlib\commands.pyo", line 920, in exception_to_return_code
  File "bzrlib\commands.pyo", line 1131, in run_bzr
  File "bzrlib\commands.pyo", line 673, in run_argv_aliases
  File "bzrlib\commands.pyo", line 695, in run
  File "bzrlib\cleanup.pyo", line 136, in run_simple
  File "bzrlib\cleanup.pyo", line 166, in _do_with_cleanups
  File "bzrlib\commands.pyo", line 1148, in ignore_pipe
  File "bzrlib\builtins.pyo", line 2884, in run
  File "bzrlib\log.pyo", line 391, in show
  File "bzrlib\log.pyo", line 419, in _show_body
  File "bzrlib\log.pyo", line 429, in _generator_factory
  File "bzrlib\log.pyo", line 443, in __init__
  File "bzrlib\tag.pyo", line 189, in get_reverse_tag_dict
  File "bzrlib\tag.pyo", line 182, in get_tag_dict
  File "bzrlib\tag.pyo", line 246, in _deserialize_tag_dict
ValueError: failed to deserialize tag dictionary 'd12:hypedyn2.1.648:<email address hidden>
du.sg-20111126171031-3csis27lnpv3n4g312:hypedyn2.1.748:<email address hidden>
111714-59quhabylmyrfmpg12:hypedyn2.2.048:<email address hidden>
rpu5b80yn12:hypedyn2.2a148:<email address hidden>:hy
pedyn2.2a248:<email address hidden>:hypedyn2.2a348:a
<email address hidden>:hypedyn2.2a548:<email address hidden>
g-20120628174748-ntlzrvus7lueotlk12:hypedyn2.2b148:<email address hidden>
15-lky5is9h2myvrytd12:hypedyn2.2b348:<email address hidden>
2noho12:hypedyn2.2b548:<email address hidden>:hypedy
n2.3a248:<email address hidden>': stream underflow

bzr 2.5.1 on python 2.6.6 (Windows-7-6.1.7601-SP1)
arguments: ['bzr', 'log']
plugins: bzrtools[2.5.0], changelog_merge[2.5.1], colo[0.4.0],
    explorer[1.2.2], fastimport[0.14.0dev], git[0.6.8], launchpad[2.5.1],
    loom[2.3.0dev], netrc_credential_store[2.5.1], news_merge[2.5.1],
    pipeline[1.4.0], qbzr[0.22.3], rewrite[0.6.4dev], svn[1.2.2],
    upload[1.2.0dev], xmloutput[0.8.8]
encoding: 'cp1252', fsenc: 'mbcs', lang: None

*** 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.