Sending a 964kB message se the presence to unavailable

Sending a 964kb message set presence to unavailable. I am sending a large message because i am using xmpp to deliver collaboration message. The message is sent by User A however user B never gets it because the unavailable presence is received first.

The flow of messages is as follow(taken from the debug window):

log for user A:

1- user A send 964kB message

2- presence is set to unavaible

3- 2 IQ messages sent 1 IQ recieved

4- IQ sent to query the roster :

5- presence is set to available

log for user B:

1- presence received user A is unavaible

2- presence received user is is available

is their a limit of how large a message can be. if not does any one know how i can get around this problem. I am using Smack version 3.0.0 and Openfire 3.3.0 both server and client running on the same window xp laptop machine with dual core and 4GB RAM.