what is "Fatal error: fatal flex scanner internal error"?

today I have been playing with php5.1.x and on 2 different machines (completely different files) I got an error rather like the one below: Fatal error: fatal flex scanner internal error--end of buffer missed in /var/www/santos/www/intranet/index.php on line 52 in each file the last 'token' in the file was a comment, in the index.php mentioned above line 52 is the last line and contains: // require_once 'end.inc.php'; is there something broken in the engine whereby the last token is not allowed to be a comment? (I never add the closing '?>' because it saves a lot of 'header outputted at <bla>' kind of errors -- has that been declared a bad thing all of a sudden?) rgds, Jochem PS: in the other file that I got the 'fatal flex scanner internal error' the last line was part of a multiline commenting out some php code as follows: //* if (defined('DEBUG') && DEBUG) {

    // output some debug info to the message handler...
    // MsgHandler::addMsg(new Msg(Msg::Debug, '_GET/_POST (merged)', pre_print(array_merge($_GET, $_POST), true)));

    if (function_exists('apc_cache_info') && ini_get('apc.enabled')) {
        MsgHandler::addMsg(new Msg(Msg::Debug, 'APC Cache Info',
                pre_print(apc_cache_info(), true)
                ));
        MsgHandler::addMsg(new Msg(Msg::Debug, 'APC SMA Info',
                pre_print(apc_sma_info(), true)
                ));
    }
    MsgHandler::addMsg(new Msg(Msg::Debug, '_GET',
            pre_print($_GET, true)
            ));
    MsgHandler::addMsg(new Msg(Msg::Debug, '_POST',
            pre_print($_POST, true)
            ));
    MsgHandler::addMsg(new Msg(Msg::Debug, '_SERVER',
            pre_print($_SERVER, true)
            ));
    MsgHandler::addMsg(new Msg(Msg::Debug, 'Make Filter',
            pre_print(Shop::getMake(), true)." ..."
            ));

} //*/