<table width="100%" border="0" cellpadding="3" cellspacing="1">
        <tr>
            <td colspan="4" >
                <strong><!--[ $lastpostcount ]-->&nbsp;<!--[ pnml name='_PNFORUM_CB_RECENTPOSTS' ]--></strong>
            </td>
        </tr>
        <!--[ foreach item=lastpost from=$lastposts ]-->
        <tr>
            <td >
                <a href="<!--[ pnmodurl modname=pnForum type=user func=viewforum forum=$lastpost.forum_id ]-->"><!--[ $lastpost.forum_name ]--></a>
            </td>
            <td >
                <a href="<!--[ pnmodurl modname=pnForum type=user func=viewtopic topic=$lastpost.topic_id start=$lastpost.start ]-->"><!--[ $lastpost.topic_title ]--></a>
            </td>
            <td >
                <!--[ $lastpost.posted_time ]-->
            </td>
            <td >
                <!--[ $lastpost.poster_name|profilelink ]-->
            </td>
        </tr>
        <!--[ /foreach ]-->
    </table>
<!--[ else ]-->
    <div ></div>
    <!--[ /if ]-->
<div >
    <a  href="<!--[ pnmodurl modname=pnForum func=main ]-->" title="<!--[ pnml name='_PNFORUM_GOTO_FORUM' ]-->"><!--[ pnml name='_PNFORUM_GOTO_FORUM' ]--></a>
</div>

// cambia la línea13 :
<a href="<!--[ pnmodurl modname=pnForum type=user func=viewtopic topic=$lastpost.topic_id start=$lastpost.start ]-->"><!--[ $lastpost.topic_title ]--></a>
 
por esta:
<a href="<!--[ pnmodurl modname=pnForum type=user func=viewtopic topic=$lastpost.topic_id start=$lastpost.start ]-->"><!--[ ((strlen($lastpost.topic_title)>12)?(substr($lastpost.topic_title,0,9)+'...') :$lastpost.topic_title) ]--></a>

<?php
// $Id: modifier.dpslicerend.php,v 1.2 2004/04/22 12:22:37 drak Exp $
// ----------------------------------------------------------------------
// PostNuke Content Management System
// Copyright (C) 2002 by the PostNuke Development Team.
// http://www.postnuke.com/
// ----------------------------------------------------------------------
// Based on:
// PHP-NUKE Web Portal System - http://phpnuke.org/
// Thatware - http://thatware.org/
// ----------------------------------------------------------------------
// LICENSE
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License (GPL)
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// To read the license please visit http://www.gnu.org/copyleft/gpl.html
// ----------------------------------------------------------------------
 
/**
 * pnRender plugin
 * 
 * This file is a plugin for pnRender, the PostNuke implementation of Smarty
 *
 * @package      Xanthia_Templating_Environment
 * @subpackage   pnRender
 * @version      $Id: modifier.dpslicerend.php,v 1.2 2004/04/22 12:22:37 drak Exp $
 * @author       The PostNuke development team
 * @link         http://www.postnuke.com  The PostNuke Home Page
 * @copyright    Copyright (C) 2002 by the PostNuke Development Team
 * @license      http://www.gnu.org/copyleft/gpl.html GNU General Public License
 */ 
 
/**
 * @author       Fernando Jordan (el_cuervo)
 * @since        26. August. 2004
 * 
 * Purpose: formats a filesize (in bytes) to human-readable format
 * <!--[]$url|dpslicerend:20]-->
 *      If $url == 'http://www.phpinsider.com/' 
 *   it outputs 'http://www.phpinsid...'
 */
function smarty_modifier_dpslicerend($string, $length = 20, $etc = '...')
{
    if ($length == 0) {
        return '';
    }
 
    if (strlen($string) > ($length + strlen($etc)) ) {
        $ret_string = strip_tags($string);
     $ret_string = substr($ret_string, 0, $length);
        $ret_string .= "...";
        return $ret_string;
    } else {
        return $string;
    }
}
 
?>