Call Current Category

The problem is that your call to query_posts is overwriting the original query for the page. You have to get the original query, then modify any params from there.

global $query_string;
// start with the original query
$myquery = wp_parse_args($query_string);
// make any changes to the query here
$myquery['posts_per_page'] = 9;
query_posts($myquery);