I justed wanted to thank you guys and post here my problem and how it was resolved with your help. Maybe it will be useful to someone else.
My previous_post_link()
was not working because of the following query_posts:
<?php query_posts('posts_per_page=2'); if (have_posts()) : ?>
So I used your fix:
$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
query_posts('posts_per_page=2&paged=' . $paged); if (have_posts()) : ?>
And now it works perfectly. Thanks again.