DLQTest is unstable with JDK 1.7

Test org.jboss.test.messaging.jms.DLQTest#testWithMessageListenerPersistent is unstable with Oracle JDK 1.7 with PostgreSQL 8.4.7.

Sometimes happens that test hangs indefinitely. Problem is in:

synchronized void waitForMessages() throws Exception

      {

         while (deliveryCount != numMessages)

         {
	    System.out.println("delivery count is: " + deliveryCount + " numberofmessages is: " + numMessages);

            this.wait();

         }

      }

where condition deliveryCount != numMessages is not reached. After initial debugging I've always ended with 50 != 80. It seems that sometimes messages are redelivered only 10 times instead of 16 times as desired.

Sometimes happens that test does not hang but fails:
1. testDLQNotAlreadyDeployed -

assertNull(dlq);

sometimes fails
2. testDefaultAndOverrideDLQ - checkEmpty(queue1); in:

            // Prompt them to go to DLQ

            cons.receive(100);



            // At this point all the messages have been delivered exactly MAX_DELIVERIES times



            checkEmpty(queue1);

detects message in the queue1 and fails the test.

Hudson job:
https://hudson.qa.jboss.com/hudson/view/EAP5/view/JBM/job/_eap5-jbm14x-rhel5-x86-64-jvm17-postgresql-84/