I had this problem, so here is what I did to solve the problem. This might or might not work for you. I think JQuery was loading twice and causing a conflict, hence why the lightbox didn't work and the image appeared in a different page.
This is the coding at the top of my joomla template (Joomla 2.5.8)
<?php /** * @copyright Copyright (C) 2012 JoomlaThemes.co - All Rights Reserved. **/
defined( '_JEXEC' ) or die( 'Restricted access' ); define( 'YOURBASEPATH', dirname(__FILE__) );
/*$jquery = $this->params->get('jquery');*/
$scrolltop = $this->params->get('scrolltop');
$superfish = $this->params->get('superfish');
As you can see from this, all I did was comment out the JQuery statement, refreshed the
page and it worked. There was obviously a conflict with two versions loading and cancelling themselves out. I haven't fully tested the site yet but the lightbox is working which is what I wanted.
I hope this helps.