Inbound Channel Adapter Polling stops after a null value received

I'm using Spring-Integration 2.0.0.M5
And below is part of my xml configuration.

Code:

---

        <inbound-channel-adapter id="processResponse" method="getSomething" ref="processMgr">
                <poller max-messages-per-poll="5">
                        <interval-trigger interval="5" time-unit="SECONDS"/>
                </poller>
        </inbound-channel-adapter>

---

getSomething may return an object or null. Whenever null is returned, the poller stops even after the interval trigger hits 5 seconds. It won't go on anymore.

Am I missing something here? I know that the poller will stop polling for message after it hits max-messages-per-poll or a null value. But it should start polling again after 5 seconds (according to the configuration above). In my case, it never polls anymore.

Are you sure it's simply returning null and not throwing an Exception?