title: Magento custom module configuration groups not collapsed
body: <p>I'm developing a custom module for Magento and I have created a configuration page for it with several groups of fields. It works ok so far but I understand that these groups should be collapsed by default but mine are all expanded when the page is loaded and only collapse when the user collapses them. </p>
  
  <p>My system.xml file:</p>
  
  <pre><code>&lt;config&gt;
      &lt;tabs&gt;
              &lt;mymoduletab translate="label" module="mymodule"&gt;
                      &lt;label&gt;My Module&lt;/label&gt;
                      &lt;sort_order&gt;400&lt;/sort_order&gt;
              &lt;/mymoduletab&gt;
      &lt;/tabs&gt;
      &lt;sections&gt;
              &lt;mymoduleoptions translate="label" module="mymodule"&gt;
                      &lt;label&gt;My Module Options&lt;/label&gt;
                      &lt;tab&gt;mymoduletab&lt;/tab&gt;
                      &lt;sort_order&gt;10&lt;/sort_order&gt;
                      &lt;show_in_default&gt;1&lt;/show_in_default&gt;
                      &lt;show_in_website&gt;1&lt;/show_in_website&gt;
                      &lt;show_in_store&gt;1&lt;/show_in_store&gt;
  
                      &lt;groups&gt;
                              &lt;basicoptions translate="label"&gt;
                                      &lt;label&gt;Basic Options&lt;/label&gt;
                                      &lt;frontend_type&gt;text&lt;/frontend_type&gt;
                                      &lt;sort_order&gt;10&lt;/sort_order&gt;
                                      &lt;show_in_default&gt;1&lt;/show_in_default&gt;
                                      &lt;show_in_website&gt;1&lt;/show_in_website&gt;
                                      &lt;show_in_store&gt;1&lt;/show_in_store&gt;
                                      &lt;fields&gt;...
  </code></pre>
  
  <p>Can anyone point out what I'm doing wrong here? Thanks. The documentation for Magento development I've been able to find are just sparse.</p>