If you give a string to query_posts, then in order to keep your pagination bit replace the query_posts call with
query_posts( $query_string . '&category_name=life' );If you don't keep the query string, then the loop won't know which page you are on and always give you the first posts. Using the array variant I gave above would be
global $wp_query;
$args = array_merge( $wp_query->query, array( 'category_name'=>'life' ) );
query_posts( $args );These snippets are equivalent and go above the loop.
