GWT button clicks getting laggy very quickly using Places/Activities in GWT2.1

Question

i'm new to GWT2.1's Places and Activities.

I'm using the same ActivityMapper as example below and getting laggy button clicks after just a few navigations.

The MVP architecture I'm using has the Presenter create listeners and define the View interface, but View objects are singletons.

Is my problem with lag due to all the listeners building up exponentially? Should I change it so that the View creates all the listeners instead? Or should I try unbinding instead?

E.g. in the GWT2.1 example here a new Activity is created every time getActivity(Place) is called.

public Activity getActivity(Place place) {
    if (place instanceof HelloPlace)
        return new HelloActivity((HelloPlace) place, clientFactory);
    else if (place instanceof GoodbyePlace)
        return new GoodbyeActivity((GoodbyePlace) place, clientFactory);
    return null;
}

Answer 1

In the end I changed the MVP architecture to the same as the example here with View defining Activity and ViewImpl containing the UI Handlers. Since the Activities no longer contain handlers and the ViewImpls are singletons the problem goes away.