To avoid scanning project's classpath too often, we listen to Java model event 'resolved classpath changed'. We expect that whenever classpath is changed so that it is necessary to update objects loaded from it, Java model sends such event when all new/modified entries are available for reading (bound to existing package roots). When such event comes, we scan classpath, and compare new set of paths with the set, which was used to load objects into models (KB, CDI, Seam, etc).
The problem is, that this event is not always comes as expected, so that issues appear (see JBIDE-8338, JBIDE-9184). For example, in new Eclipse session, when new JSP or Seam project wizard is run for the first time - the event comes. For next new project wizard invocations, it becomes a random process, for which of them the event will fail for the first time. After that, the event fails for all subsequent invocations. If we understand why it happens, it may help us improve classpath update and/or creation wizards; or report a bug to Eclipse if this behavior of Java model is not induced by our code.