Intermittent log warning messages "Setup of JMS message listener invoker failed for destination ..." in FSW 6

Issue

• I am using FSW connected to A-MQ. My SwitchYard applications are bound to A-MQ queues and topics.
• Here is my switchyard.xml:

        <sca:service name="AaaaaService" promote="AaaaaRoute/AaaaaService">
            <sca:interface.java interface="com.example.app.service.AaaaaService"/>
            <jms:binding.jms name="jms1">
                <jms:queue>queue/aaaaa</jms:queue>
                <jms:connectionFactory>#activemq/ConnectionFactory</jms:connectionFactory>
                <jms:transacted>true</jms:transacted>
                <jms:transactionManager>#jtaTransactionManager</jms:transactionManager>
            </jms:binding.jms>
        </sca:service>
        <sca:service name="BbbbbService" promote="BbbbbRoute/BbbbbService">
            <sca:interface.java interface="com.example.app.service.BbbbbService"/>
            <jms:binding.jms name="jms2">
                <jms:queue>queue/bbbbb</jms:queue>
                <jms:connectionFactory>#activemq/ConnectionFactory</jms:connectionFactory>
                <jms:transacted>true</jms:transacted>
                <jms:transactionManager>#jtaTransactionManager</jms:transactionManager>
            </jms:binding.jms>
        </sca:service>
        <sca:service name="CccccService" promote="CccccRoute/CccccService">
            <sca:interface.java interface="com.example.app.service.CccccService"/>
            <jms:binding.jms name="jms3">
                <jms:queue>queue/ccccc</jms:queue>
                <jms:connectionFactory>#activemq/ConnectionFactory</jms:connectionFactory>
                <jms:transacted>true</jms:transacted>
                <jms:transactionManager>#jtaTransactionManager</jms:transactionManager>
            </jms:binding.jms>
        </sca:service>
        ...

• These warning messages below show ever 3 seconds in the log file, filling up the logs:

2014-08-21 14:54:13,201 WARN  [org.apache.camel.component.jms.DefaultJmsMessageListenerContainer] (pool-10-thread-1) Setup of JMS message listener invoker failed for destination 'queue/aaaaa' - trying to recover. Cause: Local JMS transaction failed to commit; nested exception is javax.jms.IllegalStateException: Not a transacted session
2014-08-21 14:54:13,202 INFO  [org.apache.camel.component.jms.DefaultJmsMessageListenerContainer] (pool-10-thread-1) Successfully refreshed JMS Connection
2014-08-21 14:54:13,234 WARN  [org.apache.camel.component.jms.DefaultJmsMessageListenerContainer] (pool-9-thread-1) Setup of JMS message listener invoker failed for destination 'queue/bbbbb' - trying to recover. Cause: Local JMS transaction failed to commit; nested exception is javax.jms.IllegalStateException: Not a transacted session
2014-08-21 14:54:13,235 INFO  [org.apache.camel.component.jms.DefaultJmsMessageListenerContainer] (pool-9-thread-1) Successfully refreshed JMS Connection
2014-08-21 14:54:13,237 WARN  [org.apache.camel.component.jms.DefaultJmsMessageListenerContainer] (pool-11-thread-1) Setup of JMS message listener invoker failed for destination 'queue/ccccc' - trying to recover. Cause: Local JMS transaction failed to commit; nested exception is javax.jms.IllegalStateException: Not a transacted session
2014-08-21 14:54:13,237 INFO  [org.apache.camel.component.jms.DefaultJmsMessageListenerContainer] (pool-11-thread-1) Successfully refreshed JMS Connection

• What is the cause of the messages? Is my standalone*.xml misconfigured, or my A-MQ?