bzr keyword plugin: UnicodeDecodeError with Unicode content

bzr checkout fail with when the keyword plugin is enabled and the content is encoded in UTF-8.
I am a Windows 7 64-bit user.
I was able to workaround only when using the Python installer version for Windows as it allowed me to put a siteconfigure.py changing the the default encoding from ascii to utf-8. With the Windows standalone version I don't know if I can use a custom siteconfigure.py nor where I can put it to change the default encoding.

Sun 2011-12-18 03:55:02 -0200
0.354 bazaar version: 2.5b4
0.356 bzr arguments: [u'checkout', u'file:///C:/BazaarRoot/MSc/LaTeX_dissertacao/trunk']
0.360 looking for plugins in C:/Users/ailton/AppData/Roaming/bazaar/2.0/plugins
0.382 looking for plugins in C:/Program Files (x86)/Bazaar 2.5b4/plugins
0.665 encoding stdout as sys.stdout encoding 'cp850'
1.055 creating branch <bzrlib.branch.BzrBranchFormat7 object at 0x027366D0> in file:///C:/Users/ailton/Documents/UFABC/Mestrado/Bazaar/LaTeX_dissertacao/testing/trunk/
1.245 bzr-colo: setting nick from hook
1.568 Using fetch logic to copy between CHKInventoryRepository('file:///C:/BazaarRoot/MSc/.bzr/repository/')(RepositoryFormat2a()) and CHKInventoryRepository('file:///C:/Users/ailton/Documents/UFABC/Mestrado/Bazaar/LaTeX_dissertacao/.bzr/repository/')(RepositoryFormat2a())
1.569 fetching: <SearchResult search:(set(['<email address hidden>']), set(['null:', '<email address hidden>', '<email address hidden>']), 0)>
1.827 opening working tree 'C:/Users/ailton/Documents/UFABC/Mestrado/Bazaar/LaTeX_dissertacao/testing/trunk'
2.113 Transferred: 0kB (0.0kB/s r:0kB w:0kB)
2.114 Traceback (most recent call last):
  File "bzrlib\commands.pyo", line 923, in exception_to_return_code
  File "bzrlib\commands.pyo", line 1128, in run_bzr
  File "bzrlib\commands.pyo", line 676, in run_argv_aliases
  File "bzrlib\commands.pyo", line 698, in run
  File "bzrlib\cleanup.pyo", line 135, in run_simple
  File "bzrlib\cleanup.pyo", line 165, in _do_with_cleanups
  File "bzrlib\builtins.pyo", line 1490, in run
  File "bzrlib\branch.pyo", line 1477, in create_checkout
  File "bzrlib\bzrdir.pyo", line 832, in create_workingtree
  File "bzrlib\workingtree_4.pyo", line 1552, in initialize
  File "bzrlib\transform.pyo", line 2525, in build_tree
  File "bzrlib\transform.pyo", line 2624, in _build_tree
  File "bzrlib\transform.pyo", line 2695, in _create_files
  File "bzrlib\filters\__init__.pyo", line 169, in filtered_output_bytes
  File "C:/Users/ailton/AppData/Roaming/bazaar/2.0/plugins\keywords\keywords.py", line 259, in _normal_kw_expander
  File "C:/Users/ailton/AppData/Roaming/bazaar/2.0/plugins\keywords\keywords.py", line 254, in _kw_expander
  File "C:/Users/ailton/AppData/Roaming/bazaar/2.0/plugins\keywords\keywords.py", line 221, in expand_keywords
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 12: ordinal not in range(128)