Pagination problems

Hello,

I am kinda new to wordpress and I’ve a problem with pagination of my posts. If i try to following code the pagination works fine:

<?php
	while ( have_posts() ) : the_post();
	the_title();
	endwhile;
	posts_nav_link();
	wp_reset_query();
?>

but if I try it with some arguments it doesn’t work, because when I press on “Next Page” it shows the same result.
This is the code that doesn’t work:

<?php
	query_posts ('posts_per_page=5');
	while ( have_posts() ) : the_post();
	the_title();
	endwhile;
	posts_nav_link();
	wp_reset_query();
?>

Does anyone know what I’m doing wrong?

and Sorry for my bad English, I hope you did understand it.