title: AFNetworking, AFHTTPRequestOperation completion block slow to fire code
body: <p>I am using AFNetworking registering new users, it all works ok but on the following block I have some issues:</p>
  
  <pre><code>    AFHTTPRequestOperation *operation = [[[AFHTTPRequestOperation alloc] initWithRequest:myRequest] autorelease];
  operation.completionBlock = ^ {
      if ([operation hasAcceptableStatusCode]) {
          NSLog(@"success");
          username.backgroundColor = [UIColor yellowColor];
      } else {
          switch ([operation.response statusCode]) {
              case 421:                  
              {
                  NSLog(@"Username taken.");
                  username.backgroundColor = [UIColor yellowColor];   
              }
                  break;
              default:
                  break;
          }
      }
  };
  </code></pre>
  
  <p>Basically I my server side script does some validation and fires back a HTTP status code (I know 421 isn't a valid one). This enables me to know what went wrong on the server, this works well.</p>
  
  <p>My issue is that when the response comes back it fires the <code>NSLog(@"success");</code> or <code>NSLog(@"Username taken.");</code> straight away but any other codes fires of quite a few seconds later.</p>
  
  <p>Can anyone shed any light on this please?</p>