title: Paypal IPN always return "payment_status: Pending" on sandbox?
body: <p>I'm trying to implement PayPal on my website.</p>
  
  <p>I use this class: <a href="http://www.micahcarrick.com/php-paypal-ipn-integration-class.html" rel="noreferrer">http://www.micahcarrick.com/php-paypal-ipn-integration-class.html</a></p>
  
  <p>Right now I'm testing using the PayPal sandbox. </p>
  
  <p>Here is the problem:</p>
  
  <ol>
  <li>User makes payment  - ok</li>
  <li>User returns to my website succesfully - ok</li>
  <li>After a few seconds PayPal calls my website using IPN - ok</li>
  <li>My class successfully validate incoming IPN data.</li>
  <li>PayPal returns "payment_status: Pending" </li>
  </ol>
  
  <p>I don't know why PayPal IPN calls back with the payment status of "pending"?</p>
  
  <p>Does anyone know what I'm doing wrong?</p>