Previous/Next Page Link Not Working

[Patrice]

I noticed that my previous/next page link is not working for my blog. Even though the URL in the address bar shows the change in page number, the posts do not change.

http://leadthewayout.com/blog/


Here's my blog.php file

<?php
/*
Template Name: Blog 
*/
?>

<?php get_header(); ?>

<div id="content">

    <div id="contentleft">
    
        <div class="postarea">
    
            <div class="breadcrumb">
                <?php if (class_exists('breadcrumb_navigation_xt')) {
                echo 'Browse > ';
                // New breadcrumb object
                $mybreadcrumb = new breadcrumb_navigation_xt;
                // Options for breadcrumb_navigation_xt
                $mybreadcrumb->opt['title_blog'] = 'Home';
                $mybreadcrumb->opt['separator'] = ' / ';
                $mybreadcrumb->opt['singleblogpost_category_display'] = true;
                // Display the breadcrumb
                $mybreadcrumb->display();
                } ?>    
            </div>
            
        <!--The blog page template is currently set to show 5 posts.  Change showposts=5 to whatever number of posts you want to display.-->
            
 

<?php $page = (get_query_var('paged')) ? get_query_var('paged') : 1; query_posts("cat=13,14,15&showposts=5"); while ( have_posts() ) : the_post() ?>

            <h1><a href="<?php the_permalink() ?>" rel="bookmark"><?php the_title(); ?></a></h1>

            <div class="date">
                                
                <p>Posted by <?php the_author_nickname(); ?> &middot; <?php the_time('F j, Y'); ?></p>
            </div>


<?php the_content('[READ MORE]');?><div style="clear:both;"></div>
        
            <div class="postmeta2">
                                    
                <p>Filed Under <?php the_category(', ') ?> &middot; <?php comments_popup_link('Leave a Comment', '1 Comment', '% Comments'); ?> &nbsp;<!--<?php edit_post_link('(Edit)', '', ''); ?>--></p>
            </div>
            
            <?php endwhile; ?>
        
            <p><?php posts_nav_link(); ?></p>    
                        
        </div>
        
    </div>
<?php include(TEMPLATEPATH."/sidebar_blog.php");?>            
</div>



<!-- The main column ends  -->

<?php get_footer(); ?>