Near the end of method parse_xml_decl (in PyXML 0.8.3 this is at line
723) in _xmlplus.parsers.xmlproc.xmlutils:

        try:
            self.data = self.charset_converter(self.data)
            self.datasize = len(self.data)  ### ADD THIS LINE
        except UnicodeError, e:
            self._handle_decoding_error(self.data, e)
        self.input_encoding = enc1
