A packet handler doubt

Say I have a packet handler to handle all packets? Shouldnt all packets come to the handler and not be processed by smack at all. Are there any exceptions (sorry havent read the packet reader code)? In response to an IQ, smack seems to send an error response even though I have a packet handler for it.

For example, first I sent a presence with capability hash to notify that i am interested in receiving a tune message.

available

In response, I am getting a raw IQ packet in my handler:

Then the smack API org.jivesoftware.smackx.packet.DiscoverInfo automatically sends this message out

Where as my IQ handler is anyway sending (crafted this message using a modded IQ packet):

<feature var="[http://jabber.org/protocol/tune+notify](http://jabber.org/protocol/tune+notify)"/>

How do I ensure that my handler is the only one handling the IQ?