we are getting below error when we try to upgrade our project from Hibernate 3.x to 4.1.11. Compilation is going fine but our Junit tests are failing with below error. We could see failing statement in our debug at "entitymanager.flush()" statement. Not sure why its not cleaning particular object from entity manager after it commits, due to that Found shared references issue is occurring. Can any one help us with this how to solve this.

testTravelerCreateHistory(com.carlson.cwt.portrait.domain.history.BusinessTravelerWriteHistoryTest) Time elapsed: 0.061 sec <<< ERROR!
org.springframework.orm.hibernate3.HibernateSystemException: Found shared references to a collection: com.carlson.cwt.portrait.domain.organization.ClientOrgUnit.clientEmailAddresses; nested exception is org.hibernate.HibernateException: Found shared references to a collection: com.carlson.cwt.portrait.domain.organization.ClientOrgUnit.clientEmailAddresses
at org.springframework.orm.hibernate3.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:690)
at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:104)
at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:213)
at org.springframework.orm.jpa.JpaAccessor.translateIfNecessary(JpaAccessor.java:155)
at org.springframework.orm.jpa.JpaTemplate.execute(JpaTemplate.java:192)
at org.springframework.orm.jpa.JpaTemplate.flush(JpaTemplate.java:292)
at com.carlson.cwt.portrait.domain.traveler.dao.BusinessTravelerJpaDaoBean.flush(BusinessTravelerJpaDaoBean.java:799)
at com.carlson.cwt.portrait.domain.history.BusinessTravelerWriteHistoryTest.testTravelerCreateHistory(BusinessTravelerWriteHistoryTest.java:142)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at junit.framework.TestCase.runTest(TestCase.java:168)
at junit.framework.TestCase.runBare(TestCase.java:134)
at org.springframework.test.ConditionalTestCase.runBare(ConditionalTestCase.java:79)
at org.springframework.test.annotation.AbstractAnnotationAwareTransactionalTests.access$1(AbstractAnnotationAwareTransactionalTests.java:1)
at org.springframework.test.annotation.AbstractAnnotationAwareTransactionalTests$1.run(AbstractAnnotationAwareTransactionalTests.java:179)
at org.springframework.test.annotation.AbstractAnnotationAwareTransactionalTests.runTest(AbstractAnnotationAwareTransactionalTests.java:287)
at org.springframework.test.annotation.AbstractAnnotationAwareTransactionalTests.runTestTimed(AbstractAnnotationAwareTransactionalTests.java:258)
at org.springframework.test.annotation.AbstractAnnotationAwareTransactionalTests.runBare(AbstractAnnotationAwareTransactionalTests.java:176)
at org.springframework.test.jpa.AbstractJpaTests.runBare(AbstractJpaTests.java:195)
at com.carlson.cwt.test.AbstractCwtJpaTestCase.runBare(AbstractCwtJpaTestCase.java:56)
at org.springframework.test.jpa.AbstractJpaTests.runBare(AbstractJpaTests.java:276)
at com.carlson.cwt.test.AbstractCwtJpaTestCase.runBare(AbstractCwtJpaTestCase.java:56)
at junit.framework.TestResult$1.protect(TestResult.java:110)
at junit.framework.TestResult.runProtected(TestResult.java:128)
at junit.framework.TestResult.run(TestResult.java:113)
at junit.framework.TestCase.run(TestCase.java:124)
at junit.framework.TestSuite.runTest(TestSuite.java:243)
at junit.framework.TestSuite.run(TestSuite.java:238)
at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:83)
at org.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:62)
at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.executeTestSet(AbstractDirectoryTestSuite.java:138)
at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.execute(AbstractDirectoryTestSuite.java:125)
at org.apache.maven.surefire.Surefire.run(Surefire.java:132)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.maven.surefire.booter.SurefireBooter.runSuitesInProcess(SurefireBooter.java:308)
at org.apache.maven.surefire.booter.SurefireBooter.main(SurefireBooter.java:879)
Caused by: org.hibernate.HibernateException: Found shared references to a collection: com.carlson.cwt.portrait.domain.organization.ClientOrgUnit.clientEmailAddresses
at org.hibernate.engine.internal.Collections.processReachableCollection(Collections.java:177)
at org.hibernate.event.internal.FlushVisitor.processCollection(FlushVisitor.java:59)
at org.hibernate.event.internal.AbstractVisitor.processValue(AbstractVisitor.java:121)
at org.hibernate.event.internal.AbstractVisitor.processValue(AbstractVisitor.java:82)
at org.hibernate.event.internal.AbstractVisitor.processEntityPropertyValues(AbstractVisitor.java:76)
at org.hibernate.event.internal.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:174)
at com.carlson.cwt.portrait.domain.event.ProfileEntityFlushEventListener.onFlushEntity(ProfileEntityFlushEventListener.java:37)
at org.hibernate.event.internal.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:225)
at org.hibernate.event.internal.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:99)
at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51)
at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1213)
at org.hibernate.ejb.AbstractEntityManagerImpl.flush(AbstractEntityManagerImpl.java:996)
at org.springframework.orm.jpa.JpaTemplate$8.doInJpa(JpaTemplate.java:294)
at org.springframework.orm.jpa.JpaTemplate.execute(JpaTemplate.java:187)
... 36 more