Oops…
If you think this really should work and you can reproduce it, you should consider reporting this problem to the Trac team.
Go to http://trac.edgewall.org/ and create a new ticket where you describe the problem, how to reproduce it. Don't forget to include the Python traceback found below.
TracGuide — The Trac User and Administration Guide
Python Traceback
Traceback (most recent call last): File "/var/lib/python-support/python2.5/trac/web/main.py", line 406, in dispatch_request dispatcher.dispatch(req) File "/var/lib/python-support/python2.5/trac/web/main.py", line 237, in dispatch resp = chosen_handler.process_request(req) File "/var/lib/python-support/python2.5/trac/wiki/web_ui.py", line 135, in process_request self._render_view(req, db, page) File "/var/lib/python-support/python2.5/trac/wiki/web_ui.py", line 444, in _render_view 'page_html': wiki_to_html(page.text, self.env, req), File "/var/lib/python-support/python2.5/trac/wiki/formatter.py", line 1002, in wiki_to_html return Markup(out.getvalue()) File "/usr/lib/python2.5/StringIO.py", line 270, in getvalue self.buf += ''.join(self.buflist) UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 109: ordinal not in range(128)