previous / next links not working

I have searched Google and these forums but have not yet found an answer that solves my problem.

http://www.ribs4u.co.uk/ribs-in-stock/ this category displays a list of posts, and it is set to show 10 per page and I knwo that there are 12 posts in that category, but when clicking the “older entries” link you get the following message on http://www.ribs4u.co.uk/ribs-in-stock/page/2/ “Not Found – Sorry, but you are looking for something that isn’t here.“

I’m using a static page as the home page as defined in settings > reading settings.

Here is my home page code:

<?php get_header(); ?>
	<div id="content">
		<?php if (have_posts()) : ?>
		<?php while (have_posts()) : the_post(); ?>
		<div class="post" id="post-<?php the_ID(); ?>">
			<!--h2><a href="<?php //the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php //the_title_attribute(); ?>"><?php //the_title(); ?></a></h2>
			<small><?php //the_time('F jS, Y') ?> <!-- by <?php //the_author() ?> --></small-->
			<div class="entry clearfix">
				<?php the_content('</p><p class="moreLink">Click here for the full boat details &raquo;'); ?>
			</div>
			<!--p class="postmetadata"><?php //the_tags('Tags: ', ', ', '<br />'); ?> Posted in <?php //the_category(', ') ?> | <?php //edit_post_link('Edit', '', ' | '); ?>  <?php //comments_popup_link('No Comments »', '1 Comment »', '% Comments »'); ?></p-->
		</div>
		<?php endwhile; ?>
		<div class="navigation">
			<div class="alignleft"><?php next_posts_link('&laquo; Older Entries') ?></div>
			<div class="alignright"><?php previous_posts_link('Newer Entries &raquo;') ?></div>
		</div>
		<?php else : ?>
		<h2 class="center">Not Found</h2>
		<p class="center">Sorry, but you are looking for something that isn't here.</p>
		<?php endif; ?>
	</div>
	<?php get_sidebar(); ?>
</div>
<?php get_footer(); ?>

Can anyone please help me?