Updating the title within a SPItemEventReceiver with AfterProperties

Recently I had a problem setting the title field of a Page within the pages library. My requirement was to set the title with the value from the PageTitle field of the current item. An ItemEventReceiver, which is executed synchronously to prevent save conflict exception or problems with published items, was supposed to do exactly that. But when I set the title property of the item via AfterProperties, the value did not get stored.