PAM NodeManager operation not thread-safe

Exceptions received during deployment:

java.util.ConcurrentModificationException
at java.util.HashMap$HashIterator.nextEntry(HashMap.java:810)
at java.util.HashMap$EntryIterator.next(HashMap.java:851)
at java.util.HashMap$EntryIterator.next(HashMap.java:849)
at java.util.HashMap.writeObject(HashMap.java:1016)
at sun.reflect.GeneratedMethodAccessor101.invoke(Unknown Source)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at
java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:962)
at
java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1478)
at
java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1409)
at
java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1167)
at
java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:343)
at
org.apache.jetspeed.cluster.NodeManagerImpl.save(NodeManagerImpl.java:73)
at
org.apache.jetspeed.cluster.NodeManagerImpl.addNode(NodeManagerImpl.java:142)
at
org.apache.jetspeed.tools.pamanager.PortletApplicationManager.registerPortletApplication(PortletApplicationManager.java:388)
at
org.apache.jetspeed.tools.pamanager.PortletApplicationManager.attemptStartPA(PortletApplicationManager.java:528)
at
org.apache.jetspeed.tools.pamanager.PortletApplicationManager.tryStartPortletApplication(PortletApplicationManager.java:244)