Why does Firefox 5.0.1 not refresh this page when the back button is pressed?
See Ajax, back button and DOM updates and Restore object classes on back button in Firefox about Firefox's page cache that stores the entire state of the page and does not fire load events in most cases. If you want to avoid having Firefox save your page state (which depends upon what kind of state you have in the page), it looks like you can get it to skip it by registering an unload event for the page. Because an unload event could invalidate the page state, Firefox doesn't cache the page state if you have one and the back button will load the page freshly on the back button and all normal load events will fire.