How to show post form a single Category using query_posts

I’m trying to show only the category 4 in the first page. (http://www.taibi.it)

I’ve used the query_posts method but it still not works… it shows always the recent post

<?php
query_posts(‘cat=4’);
if ($posts) : foreach ($posts as $post) : start_wp(); ?>

<div class=”post”>
<?php require(‘post.php’); ?>
</div>
<?php endforeach; else: ?>
<p><?php _e(‘Sorry, no posts matched your criteria.’); ?></p>
<?php endif; ?>

Could anyone help me?

Greats

Davide