unicode decode error when accessing timeline

[greer@…]

i have a fresh install of trac, everything seems to be working except when i access the timeline for my project.

Trac detected an internal error: UnicodeDecodeError: 'ascii' codec can't decode byte 0xe6 in position 64: ordinal not in range(128)

File "/usr/lib/python2.5/site-packages/trac/timeline/templates/timeline.html", line 46, in <Expression u"event.render('description', context)">
  ${event.render('description', context)}
File "/usr/lib/python2.5/site-packages/trac/timeline/web_ui.py", line 288, in <lambda>
  context, field, event)
File "/usr/lib/python2.5/site-packages/trac/versioncontrol/web_ui/changeset.py", line 847, in render_timeline_event
  markup += format_to_html(self.env, context, message)
File "/usr/lib/python2.5/site-packages/trac/wiki/formatter.py", line 1095, in format_to_html
  return HtmlFormatter(env, context, wikidom).generate(escape_newlines)
File "/usr/lib/python2.5/site-packages/trac/wiki/formatter.py", line 1055, in generate
  return Markup(out.getvalue())

[Christian Boos]

Which version control backend are you using?