title: P3P and PHP session problem with iframes in Internet Explorer 9
body: <p>I have a contact form inside of an iframe, which uses captcha, and therefore requires session variables.  It works fine in every browser except IE9.  To make it work in IE8, I added the following line at the beginning of the php document:</p>
  
  <pre><code>header('P3P:CP="CAO IDC DSP COR ADM DEVi TAIi PSA PSD IVAi IVDi CONi HIS OUR IND CNT"'); 
  </code></pre>
  
  <p>However, this doesn't appear to work in IE9.  Any ideas?</p>