In my experience i have found that using the JavaScript client library for Facebook and the External Interface API in flash is alot more responsive than the Adobe Facebook AS3 library. Sometimes the event fails to fire. The only time you should use the adobe library is when you need to upload fotos, and do so by sharing the session data used by the JavaScript client.

Example of sharing a session:

fb= new Facebook();
var session:WebSession;
session=new  WebSession(Application.application.parameters.fbsigapikey,
session.addEventListener(FacebookEvent.CONNECT, function():void{
var bytes:ByteArray = jpegencoder.encode(lastpumpyourselfbm.bitmapData);
var call:UploadPhoto = new UploadPhoto(bytes);;