Images open to new window despite lightbox 2

So far I have a loop that separates post image and text to their own divs. The goal is to have a just simple photo gallery showing the post list with thumbnails, short text and opening the thumbnail to larger picture with lightbox. Problem is that the images open to a new window, you know the standard procedure.

I use the lightbox from here: https://www.huddletogether.com/projects/lightbox2/
Uploaded the files to my server and included the <script>’s to the header

The loop:

<div class="post">
 			<!-- Start the Loop. -->
    		<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
               <div id="content"> 

                    <div id="postImage">

                        <?php

                        //assign content
                        $content = get_the_content();
                        global $post;
                        $post_id = $post->ID;

                        //scrap image with links
                        preg_match_all("/<a href=\"(.*)\">(<img [^>]*>)<\/a>/",$content,$matches,PREG_PATTERN_ORDER);

                        //count number of images scraped.
                        $count = count($matches);

                        //echo out using for loop
                        for($i=0;$i<$count;$i++){
                             $match = $matches[0][$i];
                             $rel =  "<a rel='lightbox[photos]'";
                             $image = str_replace('<a',$rel,$match);
                             echo($image);
                        }
                        ?>

                    </div> 

                    <div id="postText">
                      <?php
                      ob_start();
                      the_content('Read the full post',true);
                      $postOutput = preg_replace('/<img[^>]+./','', ob_get_contents());
                      ob_end_clean();
                      echo $postOutput;
                      ?>
                    </div>

               </div>
   			 <?php endwhile; ?>
             	<div id="archiveNav" class="navigation">
                	<span class="previous-entries"><?php next_posts_link('Older Entries')?></span>
                	<span class="next-entries"><?php previous_posts_link('Newer Entries')?></span>
            	</div>
			<?php else: ?>
    			<p><?php _e('Sorry, no posts matched your criteria.'); ?></p>
    		<?php endif; ?>
   		</div>

This produces this:

<a rel='lightbox[photos]' href="https://www.mysite.com/wp-content/uploads/2011/05/wv_121.jpg"><img class="alignnone size-thumbnail wp-image-182" title="wv_121" src="https://www.mysite.com/wp-content/uploads/2011/05/wv_121-150x150.jpg" alt="" width="150" height="150" /></a>

It looks ok, though I’m such a noob.

Anyone?!