Connection closed before dataset comparison

the test is perfectly executed, but the comparison with a file after the test fails with the following stacktrace:

org.jboss.arquillian.persistence.data.dbunit.exception.DBUnitConnectionException: Unable to close connection.
at org.jboss.arquillian.persistence.data.dbunit.DBUnitPersistenceTestLifecycleHandler.closeConnection(DBUnitPersistenceTestLifecycleHandler.java:92)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.persistence.lifecycle.ErrorCollectorHandler.collectErrors(ErrorCollectorHandler.java:46)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:135)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:115)
at org.jboss.arquillian.core.impl.EventImpl.fire(EventImpl.java:67)
at org.jboss.arquillian.persistence.lifecycle.PersistenceTestTrigger.afterTest(PersistenceTestTrigger.java:100)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.invokeObservers(EventContextImpl.java:99)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:81)
at org.jboss.arquillian.testenricher.cdi.CreationalContextDestroyer.destory(CreationalContextDestroyer.java:44)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.test.impl.TestContextHandler.createTestContext(TestContextHandler.java:89)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.test.impl.TestContextHandler.createClassContext(TestContextHandler.java:75)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.test.impl.TestContextHandler.createSuiteContext(TestContextHandler.java:60)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:135)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:115)
at org.jboss.arquillian.test.impl.EventTestRunnerAdaptor.after(EventTestRunnerAdaptor.java:103)
at org.jboss.arquillian.junit.Arquillian$5$1.evaluate(Arquillian.java:245)
at org.jboss.arquillian.junit.Arquillian.multiExecute(Arquillian.java:314)
at org.jboss.arquillian.junit.Arquillian.access$100(Arquillian.java:46)
at org.jboss.arquillian.junit.Arquillian$5.evaluate(Arquillian.java:240)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
at org.jboss.arquillian.junit.Arquillian$2.evaluate(Arquillian.java:185)
at org.jboss.arquillian.junit.Arquillian.multiExecute(Arquillian.java:314)
at org.jboss.arquillian.junit.Arquillian.access$100(Arquillian.java:46)
at org.jboss.arquillian.junit.Arquillian$3.evaluate(Arquillian.java:199)
at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
at org.jboss.arquillian.junit.Arquillian.run(Arquillian.java:147)
at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
at org.junit.runner.JUnitCore.run(JUnitCore.java:136)
at org.jboss.arquillian.junit.container.JUnitTestRunner.execute(JUnitTestRunner.java:65)
at org.jboss.arquillian.protocol.servlet.runner.ServletTestRunner.executeTest(ServletTestRunner.java:160)
at org.jboss.arquillian.protocol.servlet.runner.ServletTestRunner.execute(ServletTestRunner.java:126)
at org.jboss.arquillian.protocol.servlet.runner.ServletTestRunner.doGet(ServletTestRunner.java:90)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:734)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1539)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:98)
at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:91)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:162)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:330)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:232)
at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:828)
at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:725)
at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1019)
at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:225)
at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
at java.lang.Thread.run(Thread.java:722)
Caused by: org.jboss.arquillian.core.spi.InvocationException: org.jboss.arquillian.persistence.data.dbunit.exception.DBUnitDataSetHandlingException: Failed while comparing database state with provided data sets.
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:103)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.test.impl.TestContextHandler.createClassContext(TestContextHandler.java:75)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.test.impl.TestContextHandler.createSuiteContext(TestContextHandler.java:60)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.persistence.data.dbunit.DBUnitPersistenceTestLifecycleHandler.closeConnection(DBUnitPersistenceTestLifecycleHandler.java:87)
... 106 more
Caused by: org.jboss.arquillian.persistence.data.dbunit.exception.DBUnitDataSetHandlingException: Failed while comparing database state with provided data sets.
at org.jboss.arquillian.persistence.data.dbunit.DBUnitDataHandler.compare(DBUnitDataHandler.java:115)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.invokeObservers(EventContextImpl.java:99)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:81)
at org.jboss.arquillian.test.impl.TestContextHandler.createTestContext(TestContextHandler.java:89)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.test.impl.TestContextHandler.createClassContext(TestContextHandler.java:75)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.test.impl.TestContextHandler.createSuiteContext(TestContextHandler.java:60)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.persistence.data.dbunit.DBUnitPersistenceTestLifecycleHandler.initializeDataVerification(DBUnitPersistenceTestLifecycleHandler.java:107)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:135)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:115)
at org.jboss.arquillian.core.impl.EventImpl.fire(EventImpl.java:67)
at org.jboss.arquillian.persistence.lifecycle.DataSetHandler.verifyDatabase(DataSetHandler.java:80)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.invokeObservers(EventContextImpl.java:99)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:81)
at org.jboss.arquillian.test.impl.TestContextHandler.createTestContext(TestContextHandler.java:89)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
... 122 more
Caused by: org.dbunit.dataset.DataSetException: org.postgresql.util.PSQLException: Connection has been closed.
at org.dbunit.database.DatabaseDataSet.getTable(DatabaseDataSet.java:323)
at org.jboss.arquillian.persistence.data.dbunit.DataSetComparator.compare(DataSetComparator.java:56)
at org.jboss.arquillian.persistence.data.dbunit.DBUnitDataHandler.compare(DBUnitDataHandler.java:111)
... 174 more
Caused by: org.jboss.arquillian.test.spi.ArquillianProxyException: org.postgresql.util.PSQLException : Connection has been closed. [Proxied because : Original exception not deserilizable, ClassNotFoundException]
at org.postgresql.ds.jdbc23.AbstractJdbc23PooledConnection$ConnectionHandler.invoke(AbstractJdbc23PooledConnection.java:297)
at $Proxy219.createStatement(Unknown Source)
at com.sun.gjc.spi.base.ConnectionHolder.createStatement(ConnectionHolder.java:256)
at com.sun.gjc.spi.jdbc40.ConnectionWrapper40.createStatement(ConnectionWrapper40.java:75)
at org.dbunit.database.AbstractResultSetTable.createStatement(AbstractResultSetTable.java:126)
at org.dbunit.database.AbstractResultSetTable.<init>(AbstractResultSetTable.java:97)
at org.dbunit.database.ForwardOnlyResultSetTable.<init>(ForwardOnlyResultSetTable.java:59)
at org.dbunit.database.CachedResultSetTableFactory.createTable(CachedResultSetTableFactory.java:60)
at org.dbunit.database.DatabaseDataSet.getTable(DatabaseDataSet.java:319)
... 176 more