Query posts shows only 2 posts

Hi all!

On a site I’m building, I’m trying to display all posts in the custom type “clients” in the custom category “casestudy” on top of the page, and all other (non case study) posts below.

I use two queries. The second one with all posts works just fine, but the first one only shows the two latest posts. This is the code used:

<?php
query_posts('post_type=clients&cat=19'); // load ony the case studies category
while ( have_posts() ) : the_post();
?>

<div class="client_column"><a href="<?php the_permalink(); ?>"><?php the_post_thumbnail(); ?></a></div>

<?php endwhile; ?>
<?php wp_reset_query(); ?>

What am I doing wrong? I’ve been building WP sites for over 5 years now, and never encountered this problem. I’ve flushed the permalinks cache, triple checked if necessary posts are in the right category and made sure the default amount of posts in settings is set to 20.

Any help would be very much appreciated.