title: Invalid Developer Key
body: <p>I was reaching the youtube api quota limit while building my application so I added a developer key to the request and now I get a 403 error: Invalid Developer Key.</p>
  
  <p>I've tried recreating my project and api key multiple times without any luck. I've tried adding the key to the URI as well as sending it in a header:</p>
  
  <pre><code>$c1 = curl_init($feedURL);
  curl_setopt($c1, CURLOPT_HTTPHEADER, array(
     'X-GData-Key: key=AIzaS...',
     'GData-Version: 2'
  ));
  </code></pre>
  
  <p>My application is simple, all requested data is public, so I don't see a reason to use the Zend PHP Client. </p>