title: Flex app: framerate property is NaN
body: <p>I have an AS3 App class e.g (pseudo code)</p>
  
  <pre><code>public class MyApp extends Application
  {
          protected function onRender():void
          {
              trace("frameRate = "+frameRate);
          }
  }
  </code></pre>
  
  <p>and this is then extended by the app MXML:</p>
  
  <pre><code>&lt;MyApp width="100%" height="100%" frameRate="30" enterFrame="onRender()"&gt;
  ...
  &lt;/MyApp&gt;
  </code></pre>
  
  <p>The app appears to be running at the right speed, but in MyApp.onRender(), frameRate is seen as NaN (in the debugger too if I step through).
  Why is this? How <em>should</em> I be obtaining the application's FPS property?</p>