title: New PayPal Sandbox Returns 400 Bad Request for IPN Verification
body: <p>Call it bad timing, but I had literally just gotten this working last night, right before PayPal rolled out its new developer interface.  I'm using PHP / cURL, and literally copied this code from x.com:<br>
  <a href="https://www.x.com/developers/PayPal/documentation-tools/code-sample/216623" rel="nofollow">https://www.x.com/developers/PayPal/documentation-tools/code-sample/216623</a></p>
  
  <p>At 10pm last night, it started returning 400 codes with an empty response body.  Here are the response headers:</p>
  
  <pre><code>HTTP/1.1 400 Bad Request
  Date: Fri, 08 Mar 2013 16:43:16 GMT
  Server: Apache
  X-Frame-Options: SAMEORIGIN
  Set-Cookie: c9MWDuvPtT9GIMyPc3jwol1VSlO=%7cC8szeIKENkwUqfOEYTjk-zp16RPNDC2MvLBQq9QALLYk8LcDM9kDEELRUPR_lxii1ujHBm%7cAo_aiVmV13ssvg_VFFqLkSkrVuIkUVx3O9nb09-nmQbg21hzsBAPIAIUIW8XFO_wn3c6T0%7c; domain=.paypal.com; path=/; Secure; HttpOnly
  Set-Cookie: cookie_check=yes; expires=Mon, 06-Mar-2023 16:43:16 GMT; domain=.paypal.com; path=/; Secure; HttpOnly
  Set-Cookie: Apache=10.72.109.11.1362760996493186; path=/; expires=Sun, 01-Mar-43 16:43:16 GMT
  Connection: close
  Transfer-Encoding: chunked
  Content-Type: text/plain; charset=ISO-8859-1
  </code></pre>
  
  <p>I'm using the <a href="https://developer.paypal.com/webapps/developer/applications/ipn_simulator" rel="nofollow">IPN Simulator</a> to test.  Never get a "VERIFIED" or an "INVALID" response.  Only a blank response body.  Is anyone else having this problem?</p>