bzr: ERROR: exceptions.UnicodeDecodeError: 'utf8' codec can't decode byte 0x97 in position 67: invalid start byte

Whenever tried to launch the bzr using "Bazaar Explorer" , I am getting the below error . The same is happening when I do bzr qdiff in command line too . Could you please help in finding out the issue.

Qt: Untested Windows version 6.2 detected!
bzr: ERROR: exceptions.UnicodeDecodeError: 'utf8' codec can't decode byte 0x97 in position 67: invalid start byte

Traceback (most recent call last):
  File "D:/Program Files (x86)/Bazaar/plugins\qbzr\lib\commands.py", line 176, in run
  File "D:/Program Files (x86)/Bazaar/plugins\qbzr\lib\commands.py", line 478, in _qbzr_run
  File "bzrlib\lazy_import.pyo", line 116, in __call__
  File "bzrlib\lazy_import.pyo", line 85, in _resolve
  File "bzrlib\lazy_import.pyo", line 200, in _import
  File "D:/Program Files (x86)/Bazaar/plugins\qbzr\lib\diffwindow.py", line 43, in <module>
  File "D:/Program Files (x86)/Bazaar/plugins\qbzr\lib\diff.py", line 49, in <module>
  File "D:/Program Files (x86)/Bazaar/plugins\qbzr\lib\util.py", line 128, in get_option
  File "D:/Program Files (x86)/Bazaar/plugins\qbzr\lib\util.py", line 109, in _load
  File "bzrlib\util\configobj\configobj.pyo", line 1223, in __init__
  File "bzrlib\util\configobj\configobj.pyo", line 1276, in _load
  File "bzrlib\util\configobj\configobj.pyo", line 1412, in _handle_bom
  File "bzrlib\util\configobj\configobj.pyo", line 1472, in _decode
  File "encodings\utf_8.pyo", line 16, in decode
UnicodeDecodeError: 'utf8' codec can't decode byte 0x97 in position 67: invalid start byte

bzr 2.6b1 on python 2.6.6 (Windows-post2008Server-6.2.9200)
arguments: ['bzr', 'qdiff']
plugins: bzrtools[2.5.0], changelog_merge[2.6b1], colo[0.4.0],
    explorer[1.3.0dev], fastimport[0.14.0dev], git[0.6.8dev],
    launchpad[2.6b1], loom[2.3.0dev], netrc_credential_store[2.6b1],
    news_merge[2.6b1], pipeline[1.4.0], qbzr[0.23.0dev], rewrite[0.6.4dev],
    svn[1.2.2dev], 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.