EAP5 JDK7: TestCases failing in Hibernate EntityManager due to SecurityException for prohibited package name

Testcases in PackagedEntityManageTest fails when run against JDk7 with following stacktrace:

javax.persistence.PersistenceException: [PersistenceUnit: defaultpar] Unable to configure EntityManagerFactory
at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:266)
at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:126)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:52)
at org.hibernate.ejb.test.PackagedEntityManagerTest.testDefaultPar(PackagedEntityManagerTest.java:44)
Caused by: java.lang.SecurityException: Prohibited package name: java.org.hibernate.ejb.test.pack.defaultpar
at java.lang.ClassLoader.preDefineClass(ClassLoader.java:649)
at java.lang.ClassLoader.defineClass(ClassLoader.java:785)

Hudson Link:
https://hudson.qa.jboss.com/hudson/job/eap5-hibernate-dballocator-jdk7-entitymanager/database=oracle11gR1,jdbc=jdbc4,jdk=java17_default,label=RHEL6_x86_64/lastCompletedBuild/testReport/

It is clear that packagename starts with java.* which is prohibited.
Not sure why the java. is picked up though...(could it be related to different jdk versions since we compiled the code with JDk6 and run it with JDk7)?