NPE SubscriptionManagerImpl when presence received

[ghost]

Its null pointer exception in SubscriptionManagerImpl line 66

   @Override
public void onPresenceReceived(final PresenceReceivedEvent event) {
    final Presence presence = event.getPresence();
    if (presence.getType() == Presence.Type.subscribe) {
        final XMLPacket nick = presence.getExtension("nick",     XmppNamespaces.NICK);
        eventBus.fireEventFromSource(
                new SubscriptionRequestReceivedEvent(presence.getFrom(), nick.getText()), this);
    }
}

nick is null .....
i am testing with emite 0.8-SNAPSHOT , server openfire 3.8.1, gwt .2.5.0 my request:

and response: