Handling task deadlines in container causes TX errors

Issue

• Setting a deadline-based reassignment or notification for a task causes a TX rollback at the scheduled time. To reproduce this issue, you need to set up a deadline on a task and start the process using a LocalTaskService, for example: [users:user1]@[15s] . Then the following ERROR is reported in the server log at the time of deadline:

2012-06-22 13:39:43,006 ERROR [org.jbpm.task.service.TaskService] (pool-33-thread-1) Could not start transaction.
java.lang.RuntimeException: Could not start transaction.
    at org.jbpm.task.service.TaskServiceSession.executeEscalatedDeadline(TaskServiceSession.java:1075)
    at org.jbpm.task.service.TaskService.executeEscalatedDeadline(TaskService.java:221)
    at org.jbpm.task.service.TaskService$ScheduledTaskDeadline.call(TaskService.java:359)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:98)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:206)
    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:680)
Caused by: java.lang.NullPointerException
    at org.drools.persistence.jta.JtaTransactionManager.getStatus(JtaTransactionManager.java:205)
    at org.jbpm.task.service.persistence.TaskJTATransactionManager.getStatus(TaskJTATransactionManager.java:63)
    at org.jbpm.task.service.persistence.TaskJTATransactionManager.begin(TaskJTATransactionManager.java:36)
    at org.jbpm.task.service.persistence.TaskPersistenceManager.beginTransaction(TaskPersistenceManager.java:87)
    at org.jbpm.task.service.TaskServiceSession.executeEscalatedDeadline(TaskServiceSession.java:1048)
    ... 9 more

Can you please advise me what is wrong happening here?