title: query_posts on category ID doesn't work
body: <pre><code>$posts = query_posts(array('post_type'=&gt;'sedan', 'category'=&gt;'1', 'posts_per_page'=&gt;'4'));
  </code></pre>
  
  <p>The <code>category</code> parameter in the above query doesn't seem to work as expected. It is showing all the posts from <code>Sedan</code> post type, but I want to specify only categories with <code>category ID = 1</code> within <code>Sedan post type</code>.</p>