probability command raises UnicodeDecodeError exception

2010-05-05 21:57:48-0300 [-] FROM 1: 2010-05-05 21:57:48-0300 [-] Unhandled Error
2010-05-05 21:57:48-0300 [-] FROM 1: Traceback (most recent call last):
2010-05-05 21:57:48-0300 [-] FROM 1: File "/usr/lib/python2.6/dist-packages/twisted/internet/defer.py", line 371, in _runCallbacks
2010-05-05 21:57:48-0300 [-] FROM 1: self.result = callback(self.result, *args, **kw)
2010-05-05 21:57:48-0300 [-] FROM 1: File "/usr/lib/python2.6/dist-packages/twisted/internet/defer.py", line 879, in gotResult
2010-05-05 21:57:48-0300 [-] FROM 1: _inlineCallbacks(r, g, deferred)
2010-05-05 21:57:48-0300 [-] FROM 1: File "/usr/lib/python2.6/dist-packages/twisted/internet/defer.py", line 823, in _inlineCallbacks
2010-05-05 21:57:48-0300 [-] FROM 1: result = g.send(result)
2010-05-05 21:57:48-0300 [-] FROM 1: File "/usr/local/lib/python2.6/dist-packages/ampirc.py", line 383, in handleCommand
2010-05-05 21:57:48-0300 [-] FROM 1: proto.handleCommand(cmd, prefix, params)
2010-05-05 21:57:48-0300 [-] FROM 1: --- <exception caught here> ---
2010-05-05 21:57:48-0300 [-] FROM 1: File "/usr/lib/python2.6/dist-packages/twisted/words/protocols/irc.py", line 2331, in handleCommand
2010-05-05 21:57:48-0300 [-] FROM 1: method(prefix, params)
2010-05-05 21:57:48-0300 [-] FROM 1: File "/usr/lib/python2.6/dist-packages/twisted/words/protocols/irc.py", line 1815, in irc_PRIVMSG
2010-05-05 21:57:48-0300 [-] FROM 1: self.privmsg(user, channel, message)
2010-05-05 21:57:48-0300 [-] FROM 1: File "infobat/irc.py", line 265, in privmsg
2010-05-05 21:57:48-0300 [-] FROM 1: command_func(target, channel_obj, *s_command[1:])
2010-05-05 21:57:48-0300 [-] FROM 1: File "infobat/irc.py", line 534, in infobat_probability
2010-05-05 21:57:48-0300 [-] FROM 1: min(probabilities) * 100, max(probabilities) * 100)
2010-05-05 21:57:48-0300 [-] FROM 1: exceptions.UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 27: ordinal not in range(128)