Thanks for the quick response! Here are the sources (I had to 'censor' it for obvious reasons):

MDB:

@MessageDriven(name = "Processor", activationConfig = {
 @ActivationConfigProperty(propertyName = "destinationType", propertyValue = "javax.jms.Queue"),
 @ActivationConfigProperty(propertyName = "destination", propertyValue = "myqueue"),
 @ActivationConfigProperty(propertyName = "providerAdapterJNDI", propertyValue="java:/TIBCOJMSProvider")
})
public class Receiver implements MessageListener {

 @Resource
 private MessageDrivenContext context;

 /**
 * Controller does the actual processing
 * of the incoming message
 */
 @EJB
 private Creator creator;

 /**
 * @see javax.jms.MessageListener#onMessage(javax.jms.Message)
 */
 public void onMessage(Message msg) {
 try {
 TextMessage txtMsg = (TextMessage)msg;
 String text = txtMsg.getText();
 creator.process(text);
 } catch (JMSException e) {
 e.printStackTrace();
 context.setRollbackOnly();
 } catch (ValidationException e) {
 e.printStackTrace();
 context.setRollbackOnly();
 }
 }

 /**
 * @param creator the controller to set
 */
 public void setCreator(Creator creator) {
 this.creator = creator;
 }

 /**
 * @param context the context to set
 */
 public void setContext(MessageDrivenContext context) {
 this.context = context;
 }

}

@Local
public interface Creator {

 /**
 * Processed an incoming message bus from a message bus
 * and stores it in database.
 *
 * @param text
 * @throws ValidationException
 * @return an instance of saved entity
 */
 public Entiteit process(String text) throws ValidationException;

 /**
 * Sets entity manager
 * @param em
 */
 public void setDatabase(EntityManager em);

 /**
 * Retrieves entity manager
 * @return entity manager instance
 */
 public EntityManager getDatabase();

}

/**
 * Processes entities
 *
 */
@Stateless
@Name("Creator")
public class CreatorBean implements Creator {

 private EntityManager em;

 /**
 * Sets entity manager
 * @param em
 */
 @PersistenceContext
 public void setDatabase(EntityManager em){
 this.em = em;
 }

 /**
 * Retrieves entity manager
 * @return entity manager instance
 */
 public EntityManager getDatabase() {
 return this.em;
 }

 /**
 * Processes the entities from xml and stores it in database.
 * It also performs checking on existing records end replaces them if found.
 * @throws ValidationException
 */
 public Entiteit process(String xmlText) throws ValidationException {
 Entiteit en = null;

 try {
 IBindingFactory bfact = BindingDirectory.getFactory(Entiteit.class);
 IUnmarshallingContext uctx = bfact.createUnmarshallingContext();

 StringReader sr = new StringReader(xmlText);

 en = (Entiteit) uctx.unmarshalDocument( sr, null);

 em.persist(en);


 } catch (JiBXException e) {
 throw new ValidationException("Error processing incoming entity", e);
 }

 return en;
 }

}

Is there a problem with the way I use it or should I create a JIRA issue?

Created a JIRA issue: http://jira.jboss.com/jira/browse/JBSEAM-2286