title: Wordpress posts_per_page not working
body: <p>So, I tried all the "add_filter" things on the whole web to get this right but it doesn't work! It always shows me more than 1 post. What's wrong with my code? Latest WP-Version 4.1.1 and no plugins installed.</p>
  
  <p>Here is the code:</p>
  
  <pre><code>&lt;?php
  
      $sticky = get_option('sticky_posts');
  
      if ( !empty($sticky) ) {
  
      $args = array(
          'post__in' =&gt; $sticky,
          'orderby' =&gt; 'date',
          'order' =&gt; 'ASC',
          'posts_per_page' =&gt; 1
      );
  
      $slider_query = new WP_Query( $args );
  
      while ( $slider_query-&gt;have_posts() ) {             
          $slider_query-&gt;the_post();
      ?&gt;
  
      &lt;div&gt;
         &lt;!-- here we go --&gt;
      &lt;/div&gt;
  
  &lt;?php
  
          }
      }
  
  ?&gt;
  </code></pre>