TypeError in _get_filter_stack_for when using svn-keywords

I'm attempting to use svn-keywords to fill in svn keywords in a bzr checkout. Setting the rules to:

[name *]
svn-keywords = Id, Rev, URL

Causes the following to be reported whenever I attempt to switch branches:
bzr: ERROR: exceptions.TypeError: list objects are unhashable

Traceback (most recent call last):
  File "bzrlib\commands.pyo", line 853, in exception_to_return_code
  File "bzrlib\commands.pyo", line 1055, in run_bzr
  File "bzrlib\commands.pyo", line 661, in run_argv_aliases
  File "bzrlib\commands.pyo", line 665, in run_direct
  File "bzrlib\cleanup.pyo", line 122, in run_simple
  File "bzrlib\cleanup.pyo", line 156, in _do_with_cleanups
  File "bzrlib\builtins.pyo", line 5519, in run
  File "bzrlib\switch.pyo", line 40, in switch
  File "bzrlib\switch.pyo", line 138, in _update
  File "bzrlib\merge.pyo", line 755, in __init__
  File "bzrlib\merge.pyo", line 766, in do_merge
  File "bzrlib\cleanup.pyo", line 118, in run
  File "bzrlib\cleanup.pyo", line 156, in _do_with_cleanups
  File "bzrlib\merge.pyo", line 772, in _do_merge
  File "bzrlib\merge.pyo", line 814, in _compute_transform
  File "bzrlib\merge.pyo", line 1302, in _do_merge_contents
  File "bzrlib\merge.pyo", line 1386, in merge_contents
  File "bzrlib\merge.pyo", line 1369, in _default_other_winner_merge
  File "bzrlib\transform.pyo", line 2532, in create_from_tree
  File "bzrlib\tree.pyo", line 677, in _content_filter_stack
  File "bzrlib\filters\__init__.pyo", line 245, in _get_filter_stack_for
TypeError: list objects are unhashable

bzr 2.1.1 on python 2.5.4 (Windows-XP-5.1.2600-SP3)
arguments: ['bzr', 'switch', '..\\features\\shim-repair']
encoding: 'cp1252', fsenc: 'mbcs', lang: None
plugins:
  bzrtools C:\Program Files\Bazaar\plugins\bzrtools [2.1.0]
  explorer C:\Program Files\Bazaar\plugins\explorer [1.0.1]
  launchpad C:\Program Files\Bazaar\plugins\launchpad [2.1.1]
  netrc_credential_store C:\Program Files\Bazaar\plugins\netrc_credential_store [2.1.1]
  news_merge C:\Program Files\Bazaar\plugins\news_merge [2.1.1]
  qbzr C:\Program Files\Bazaar\plugins\qbzr [0.18.4]
  rebase C:\Program Files\Bazaar\plugins\rebase [0.5.5]
  svn C:\Program Files\Bazaar\plugins\svn [1.0.2]
  upload C:\Program Files\Bazaar\plugins\upload [1.0.0dev]
  xmloutput C:\Program Files\Bazaar\plugins\xmloutput [0.8.7.dev]

*** 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.