Openfire server 4.0 , pep based avatars

I have been working with openfire 4.0 and I am trying to implement the pep based avatars , I could get everything to work except , the problem is that the server simply ignores my IQ packet , nothing in the error log , all.log at all, Can any one help me with this or any specific XMPP stanza attributes we need to specify.

After some digging I have found the stack trace from the error generated by openfire server :

org.jivesoftware.openfire.handler.IQHandler - Internal server error

java.lang.NullPointerException

at org.jivesoftware.openfire.pubsub.PubSubEngine.createNodeHelper(PubSubEngine.jav a:1165)

at org.jivesoftware.openfire.pubsub.PubSubEngine.publishItemsToNode(PubSubEngine.j ava:340)

at org.jivesoftware.openfire.pubsub.PubSubEngine.process(PubSubEngine.java:98)

at org.jivesoftware.openfire.pep.PEPServiceManager.process(PEPServiceManager.java: 215)

at org.jivesoftware.openfire.pep.IQPEPHandler.handleIQ(IQPEPHandler.java:423)