Exclude posts in certain categories for custom post type

query_posts('post_type=For_Sale&order=ASC&nopaging=true&cat=-24');

I am using the above query to return every post with the custom type of ‘For_Sale’. I need to exclude category 24, but adding ‘cat=-24’ has no affect. What am I missing?

This is my code for the custom type and taxonomy, just in case I’ve made a mistake here:

//Add For Sale custom type and associated taxonomies

add_action('init', 'tap_forsale_custom_type');
function tap_forsale_custom_type()
{
  $labels = array(
    'name' => _x('For Sale', 'post type general name'),
    'singular_name' => _x('For_Sale', 'post type singular name'),
    'add_new' => _x('Add Post', 'For_Sale'),
    'add_new_item' => __('Add For Sale Post'),
    'edit_item' => __('Edit For Sale Post'),
    'new_item' => __('New For Sale Post'),
    'view_item' => __('View For Sale Post'),
    'search_items' => __('Search For Sale Posts'),
    'not_found' =>  __('No For Sale Posts found'),
    'not_found_in_trash' => __('No For Sale Posts found in Trash'),
    'parent_item_colon' => ''
  );
  $args = array(
    'labels' => $labels,
    'public' => true,
    'publicly_queryable' => true,
    'show_ui' => true,
    'query_var' => true,
    'rewrite' => true,
    'capability_type' => 'post',
    'hierarchical' => false,
    'menu_position' => 5,
    'supports' => array('title','editor','revisions','custom-fields')

  );
  register_post_type('For_Sale',$args);
}

add_action( 'init', 'create_forsale_taxonomies', 0 );

function create_forsale_taxonomies()
{
  // Add new taxonomy, make it hierarchical (like categories)
  $labels = array(
    'name' => _x( 'Categories', 'taxonomy general name' ),
    'singular_name' => _x( 'Categories', 'taxonomy singular name' ),
    'search_items' =>  __( 'Search "For Sale" Categories' ),
    'all_items' => __( 'All Categories' ),
    'parent_item' => __( 'Parent Category' ),
    'parent_item_colon' => __( 'Parent Category:' ),
    'edit_item' => __( 'Edit  "For Sale" Category' ),
    'update_item' => __( 'Update "For Sale" Category' ),
    'add_new_item' => __( 'Add New "For Sale" Category' ),
    'new_item_name' => __( 'New "For Sale" Category' ),
  ); 	

  register_taxonomy('fs_categories',array('For_Sale'), array(
    'hierarchical' => false,
    'labels' => $labels,
    'show_ui' => true,
    'query_var' => true,
    'rewrite' => array( 'slug' => 'For Sale' ),
  ));
};