"The pool has been shutdown" error message in JBoss EAP 5

Issue

The following error is observed in the JBoss server log:

    javax.resource.ResourceException: Unable to get managed connection for JmsXA
       at org.jboss.resource.connectionmanager.BaseConnectionManager2.getManagedConnection(BaseConnectionManager2.java:441)
       at org.jboss.resource.connectionmanager.TxConnectionManager.getManagedConnection(TxConnectionManager.java:424)
       at org.jboss.resource.connectionmanager.BaseConnectionManager2.allocateConnection(BaseConnectionManager2.java:496)
       at org.jboss.resource.connectionmanager.BaseConnectionManager2$ConnectionManagerProxy.allocateConnection(BaseConnectionManager2.java:941)
       at org.jboss.resource.adapter.jms.JmsSessionFactoryImpl.allocateConnection(JmsSessionFactoryImpl.java:395)
       at org.jboss.resource.adapter.jms.JmsSessionFactoryImpl.createQueueSession(JmsSessionFactoryImpl.java:145)
       at com.aaa.bbb.idoc.impl.IDocServiceBean.sendIDocMessage(IDocServiceBean.java:189)
       at com.aaa.bbb.idoc.impl.IDocServiceBean.parseAndSendIDocs(IDocServiceBean.java:109)
     Caused by: org.jboss.resource.connectionmanager.RetryableResourceException: The pool has been shutdown
       at org.jboss.resource.connectionmanager.InternalManagedConnectionPool.getConnection(InternalManagedConnectionPool.java:207)
       at org.jboss.resource.connectionmanager.JBossManagedConnectionPool$BasePool.getConnection(JBossManagedConnectionPool.java:747)
       at org.jboss.resource.connectionmanager.BaseConnectionManager2.getManagedConnection(BaseConnectionManager2.java:404)
       ... 120 more