Specific category pagination problem

Hi,

My blog default amount of posts per page is 20. There is a specific category where I want only 10 posts instead of the default.

I did a custom template for that category (category-71.php) with this code:

$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
query_posts($query_string.'&posts_per_page=10&paged='.$paged);

When that category got it’s 11th post, the “next posts” link showed up but when I click on it the /page/2/ calls the 404.php template.

This second page only works when the amount of posts goes over 20 posts.

What setting am I missing?