Using exclude on category listing is busted

I've cloned the default category listing widget开发者_开发知识库 so that I can exclude listing any category whose parent is the default uncategorized category (cat_ID = 1).

Here's my code, however, its not working. I still have items being listed even though their parent category is "uncategorized"...

    $cat_args['title_li'] = '';
    $cat_args['exclude'] = '1';
    wp_list_categories(apply_filters('widget_categories_args', $cat_args));

I may not be understanding exactly what you want to do, but could you not use 'exclude_tree'?

wp_list_categories('title_li=&exclude_tree=1');