Exception when rolling back transaction - commit when aborted

In logs after you render the main view and wait a little bit, you should be able to see errors like:
11:47:03,379 ERROR [UpdateManager] Exception when rolling back the transaction
java.util.EmptyStackException
at java.util.Stack.peek(Stack.java:85)
at java.util.Stack.pop(Stack.java:67)
at org.jboss.seam.transaction.SeSynchronizations.afterTransactionRollback(SeSynchronizations.java:45)
at org.jboss.seam.transaction.UTTransaction.rollback(UTTransaction.java:70)
at org.jboss.blog.session.update.UpdateThread.executeInTransaction(UpdateThread.java:102)
at org.jboss.blog.session.update.UpdateThread.run(UpdateThread.java:41)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
at java.util.concurrent.FutureTask$Sync.innerRunAndReset(FutureTask.java:317)
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:150)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$101(ScheduledThreadPoolExecutor.java:98)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.runPeriodic(ScheduledThreadPoolExecutor.java:181)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:205)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:637)

In fact this is just the least interesting exception as all other are being consumed and not thrown or displayed only in webadmin. Nevertheless if you print out those remining you will get:
11:47:03,376 WARN [arjLoggerI18N] [com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator_4] TwoPhaseCoordinator.afterCompletion - returned failure for com.arjuna.ats.internal.jta.resources.arjunacore.SynchronizationImple@76ef1d4c
11:47:03,378 ERROR [UpdateManager] Exception in transaction
javax.transaction.RollbackException: [com.arjuna.ats.internal.jta.transaction.arjunacore.commitwhenaborted] [com.arjuna.ats.internal.jta.transaction.arjunacore.commitwhenaborted] Can't commit because the transaction is in aborted state
at com.arjuna.ats.internal.jta.transaction.arjunacore.TransactionImple.commitAndDisassociate(TransactionImple.java:1418)
at com.arjuna.ats.internal.jta.transaction.arjunacore.BaseTransaction.commit(BaseTransaction.java:134)
at com.arjuna.ats.jbossatx.BaseTransactionManagerDelegate.commit(BaseTransactionManagerDelegate.java:87)
at org.jboss.tm.usertx.client.ServerVMClientUserTransaction.commit(ServerVMClientUserTransaction.java:146)
at org.jboss.seam.transaction.UTTransaction.commit(UTTransaction.java:52)
at org.jboss.blog.session.update.UpdateThread.executeInTransaction(UpdateThread.java:94)
at org.jboss.blog.session.update.UpdateThread.run(UpdateThread.java:41)