Comments on category pages

Reading through the various posts problems with the comments seems to be a regular problem but I can’t find the solution to my problem. Can someone help please.

When reading a post (presumably using the single.php template) readers can post comments but I have a template for a specific category – category-6.php and I would like to display the latest post and have a comment box. My attempt is:

<?php
/**
* @package WordPress
* @subpackage Default_Theme
*/
get_header();
?>

<div id=”content”>
<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
<div class=”navigation”>
<div class=”alignleft”><?php previous_post_link(‘« %link’) ?></div>
<div class=”alignright”><?php next_post_link(‘%link »’) ?></div>
</div>
<div <?php post_class() ?> id=”post-<?php the_ID(); ?>”>
<h2><?php the_title(); ?></h2>
<div class=”entry”>
<?php the_content(‘<p class=”serif”>Read the rest of this entry »</p>’); ?>
<?php wp_link_pages(array(‘before’ => ‘<p>Pages: ‘, ‘after’ => ‘</p>’, ‘next_or_number’ => ‘number’)); ?>
<?php the_tags ( ‘<p>Tags: ‘, ‘, ‘, ‘</p>’); ?>
</div>
</div>
<?php comments_template(); ?>
<?php endwhile; else: ?>
<p>Sorry, no posts matched your criteria.</p>
<?php endif; ?>
</div>
</div>
<?php get_footer(); ?>

While this does display the latest post it doesn’t display a comment box.

Can anyone point me in the right dorection please.