I'm getting HibernateException Javassist Enhancement failed

Issue

• Under heavy read-only load operations, following exception is raised

  2010-02-25 13:01:17,384 ERROR
  [xxx]
  javax.persistence.PersistenceException:
  org.hibernate.HibernateException: Javassist Enhancement failed:
  cxxx
          at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:629)
          at org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:75)
  Caused
  by: org.hibernate.HibernateException: Javassist Enhancement failed:
  xxx.Cu03tb01
          at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.getProxy(JavassistLazyInitializer.java:118)
  ...
          at org.hibernate.loader.custom.CustomLoader.list(CustomLoader.java:289)
          at org.hibernate.impl.SessionImpl.listCustomQuery(SessionImpl.java:1695)
          at org.hibernate.impl.AbstractSessionImpl.list(AbstractSessionImpl.java:142)
          at org.hibernate.impl.SQLQueryImpl.list(SQLQueryImpl.java:152)
          at org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:66)
          ... 65 more
  Caused
  by: java.lang.RuntimeException: javax.naming.NameNotFoundException:
  SessionIdentifer.org.jboss.ejb3.entity.TransactionScopedEntityManager@1900716037
  not bound