Archive Page 404 problem

Hello. I am having an issue with paging archives. Below is the code I am using:

$post_obj = $wp_query->get_queried_object();
                $args = array(
                  'cat' => $post_obj->cat_ID,
                  'posts_per_page' => 3,
                  'paged' => $paged
                );

                query_posts($args);

When you click the “Next Page” link you get 404. I have found other posts about this but none of the solutions seem to fix my issue. I have also tried the following:

$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
                $post_obj = $wp_query->get_queried_object();
                $args = array(
                  'cat' => $post_obj->cat_ID,
                  'posts_per_page' => 3,
                  'paged' => $paged
                );

                query_posts($args);

No luck with that either. Any help would be very much appreciated.