Remoting subsystem: Concurrent modification exception during server shutdown

Jitka Kozana reports that the following exception was sometimes logged during server shutdown:

[0m�[33m01:46:29,696 WARN [org.jboss.msc.service.fail] (MSC service thread 1-55) MSC000004: Failure during stop of service jboss.remoting.endpoint.management.channel.management: java.util.ConcurrentModificationException
at java.util.HashMap$HashIterator.nextEntry(HashMap.java:793) [rt.jar:1.6.0_45]
at java.util.HashMap$KeyIterator.next(HashMap.java:828) [rt.jar:1.6.0_45]
at java.util.AbstractCollection.addAll(AbstractCollection.java:305) [rt.jar:1.6.0_45]
at java.util.HashSet.<init>(HashSet.java:100) [rt.jar:1.6.0_45]
at org.jboss.as.remoting.AbstractChannelOpenListenerService.stop(AbstractChannelOpenListenerService.java:123)
at org.jboss.msc.service.ServiceControllerImpl$StopTask.stopService(ServiceControllerImpl.java:1911) [jboss-msc-1.0.4.GA-redhat-1.jar:1.0.4.GA-redhat-1]
at org.jboss.msc.service.ServiceControllerImpl$StopTask.run(ServiceControllerImpl.java:1874) [jboss-msc-1.0.4.GA-redhat-1.jar:1.0.4.GA-redhat-1]
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895) [rt.jar:1.6.0_45]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918) [rt.jar:1.6.0_45]
at java.lang.Thread.run(Thread.java:662) [rt.jar:1.6.0_45]