NPE in Observation when listener restricted by node type and property deleted

Assume that a node type "uscdr:file" has been defined in a .cnd file loaded at startup. An event listener is added as follows: int EVENT_MASK = Event.NODE_REMOVED | Event.PROPERTY_ADDED | Event.PROPERTY_REMOVED; session.getWorkspace().getObservationManager().addEventListener(this, EVENT_MASK, null, true, null, new String[] {"uscdr:file"}, false); Now, if a property is deleted from a node of type uscdr:file, the following NPE occurs: 21:43:55,988 ERROR [STDERR] Exception in thread "pool-12-thread-1" java.lang.NullPointerException 21:43:55,988 ERROR [STDERR] at org.modeshape.jcr.JcrObservationManager$JcrListenerAdapter.acceptBasedOnNodeTypeName(JcrObservationManager.java:814) 21:43:55,988 ERROR [STDERR] at org.modeshape.jcr.JcrObservationManager$JcrListenerAdapter.notify(JcrObservationManager.java:1006) 21:43:55,988 ERROR [STDERR] at org.modeshape.graph.observe.NetChangeObserver.notify(NetChangeObserver.java:362) 21:43:55,989 ERROR [STDERR] at org.modeshape.jcr.JcrObservationManager$JcrListenerAdapter.notify(JcrObservationManager.java:975) 21:43:55,989 ERROR [STDERR] at org.modeshape.jcr.JcrRepository$RepositoryObservationManager$1.run(JcrRepository.java:1974) 21:43:55,989 ERROR [STDERR] at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) 21:43:55,989 ERROR [STDERR] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) 21:43:55,989 ERROR [STDERR] at java.lang.Thread.run(Thread.java:662) and the EventListener is never invoked. The following code avoids the NPE: int EVENT_MASK = Event.NODE_REMOVED | Event.PROPERTY_ADDED | Event.PROPERTY_REMOVED; session.getWorkspace().getObservationManager().addEventListener(this, EVENT_MASK, null, true, null, null, false);