In this scenario, a page uses a Window Scoped bean. This bean uses the @PreDestroy annotation. If the page is closed before it has a chance to finish loading this annotated method is not called. This also puts the state of new bean instances out of sync.

The scenario is as follows with some logging:
 - Page is loaded and allowed to finish rendering and the page is closed.
TestBean Constructor Called 31768553
PostConstruct Called 31768553
PreDestroy Called 31768553
 - The page is loaded again but this time it is closed before it finishes loading.
TestBean Constructor Called 32617693
PostConstruct Called 32617693
 - A new page instance is loaded and allowed to finish.
TestBean Constructor Called 1021952
PostConstruct Called 1021952
 - The previous page is closed and a new one is opened. In this instance the previous page bean is cleared when the new instance is loaded.
PreDestroy Called 1021952
TestBean Constructor Called 21790214
PostConstruct Called 21790214
 - The first bean instance (32617693) that is closed before finished loading never calls it's PreDestroy method.