title: Random Facebook iOS SDK auth token invalidated by API
body: <p>I randomly get the following message when trying to access the graph from my iPhone using Facebook iOS SDK:</p>
  
  <blockquote>
    <p>response string: {"error":{"type":"OAuthException","message":"Error validating access token: The session was invalidated explicitly using an API call."}}</p>
  </blockquote>
  
  <p>I'm not sure why this is because I call the graph immediately after I login, so the token should be valid.  Also, this happens randomly around 30% of the time.  Does anyone know how to go about debugging this issue?</p>