Yeah!!! thanks, that fixed it!…
here is the final code, if someone is having the same problem.
<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
<!-- POST STUFF -->
<?php endwhile; else: ?>
<!-- 404 STUFF -->
<?php endif; ?>
<?php $my_query = new WP_Query('cat=X&showposts=5');
while ($my_query->have_posts()) : $my_query->the_post();
$do_not_duplicate = $post->ID;?>
<!-- 5 LATEST POST STUFF -->
<?php endwhile; ?>
<?php if (have_posts()) : while (have_posts()) : the_post();
update_post_caches($posts); ?>
<!-- COMMENTS STUFF -->
<?php endwhile; endif; ?>
where X is the Cat ID