wordpress - Out of Memory Listing Custom Post type in Admin? -

this strange , serious problem. going "all images" in admin area (equivalent of posts) shows memory exhausted error, , white screen. , after upping memory high amount.

i guess wondering why memory needed build list?

i assume must error on part, coding. perhaps i've done wrong in declaring post type? common "gotchas" in area? i'd hate "increase memory" because seems weak work around serious problem.

add_filter( 'manage_edit-image_columns', 'symbiostock_image_manager_edit_columns' ); function symbiostock_image_manager_edit_columns( $columns ) {     $columns = array(          'cb' => '<input type="checkbox" />',         'image_preview' => 'preview',         'date' => 'uploaded',         'title' => 'image name',         'description' => 'description',         'exclusive' => 'exclusive',         'price_bloggee' => 'bloggee',         'price_small' => 'small',         'price_medium' => 'medium',         'price_large' => 'large',         'price_vector' => 'vector',         'cat' => 'category',         'tag' => 'keywords'      );      return $columns; }  add_action( 'manage_image_posts_custom_column', 'symbiostock_image_manager_custom_columns' ); function symbiostock_image_manager_custom_columns( $column ) {     global $post;      $custom = get_post_custom();      switch ( $column ) {           case 'date':                          break;                case 'image_preview':              echo '<img class="admin_preview_pic" alt="image preview" src="' . $custom['symbiostock_minipic'][0] . '" />';              break;          case 'description':              the_excerpt();              break;          case 'exclusive':              echo $exclusive = ucwords(str_replace('_', ' ', $custom[ "exclusive" ][ 0 ]));              break;          case 'discount_percent':              echo $discount_percent = $custom[ "discount_percent" ][ 0 ];              break;          case 'price_bloggee':              echo $price_bloggee = $custom[ "price_bloggee" ][ 0 ];               break;          case 'price_small':              echo $custom[ "price_small" ][ 0 ];              break;          case 'price_medium':              echo $custom[ "price_medium" ][ 0 ];              break;          case 'price_large':              echo $custom[ "price_large" ][ 0 ];              break;          case 'price_vector':              echo $custom[ "price_vector" ][ 0 ];              break;          case 'cat':              echo get_the_term_list( $post->id, 'image-type', '', ', ', '' );              break;          case 'tag':              echo get_the_term_list( $post->id, 'image-tags', '', ', ', '' );              break;      } //$column     } 

maybe there problem on how i've declared custom post type. here's code in case:

register_taxonomy( 'image-tags', array(      'image'  ), array(      'hierarchical' => false,      'rewrite' => true,      'query_var' => true,     'singular_label' => 'image keyword',     'exclude_from_search' =>false,     'hierarchical'            => false,     'labels'                  => $labels,     'show_ui'                 => true,     'show_admin_column'       => true,      'slug' => 'image-tag',                    'labels' => array(         'name' => _x( 'image keywords', 'taxonomy general name' ),         'singular_name' => _x( 'keywords', 'taxonomy singular name' ),         'search_items' =>  __( 'search images' ),         'all_items' => __( 'all image keywords' ),         'edit_item' => __( 'edit image keyword' ),         'update_item' => __( 'update image keyword' ),         'add_new_item' => __( 'add new image keyword' ),         'new_item_name' => __( 'new keyword name' ),         'menu_name' => __( 'image keywords' ),         ),     'rewrite' => array(         'slug' => 'search-images', // controls base slug display before each term         'with_front' => false,      ), ) );