title: Zend_Form_Element_Hash problem (unclear documentation?)
body: <p>It is written in the documentation that it is enough to include the Zend_Form_Element_Hash element in a form and that CSRF protection is handled automatically by Zend_Form.</p>
  
  <p>I have added the token like this:</p>
  
  <pre><code>$token = new Zend_Form_Element_Hash('security_token_against_csrf');
  $token-&gt;setSalt($this-&gt;_helper-&gt;randomString());
  $form-&gt;addElement($token);
  </code></pre>
  
  <p>But after submitting any form with such token I get this error:</p>
  
  <pre><code>The two given tokens do not match
  </code></pre>
  
  <p>Do I need to use any method during the form validation as well?</p>