HELP::SIP MESSAGE (RFC 3428) / NOTIFY don't pass over

Hi,

I need help for the following issue:

I try to send “Instand text messages” from one SIP Client (XTen eyeBeam) to an other. Asterisk ignore this, and drop the packet’s.
What can i do/program (perhebs in c) to able this function ?
Or is this a configuration issue ?

Here is the capture:

MESSAGE sip:4002@10.0.0.50 SIP/2.0
To: sip:4002@10.0.0.50
From: Joe Schmoesip:4000@mydomain.com;tag=d1059619
Via: SIP/2.0/UDP 10.0.0.120:9366;branch=z9hG4bK-d87543-647645781-1–d87543-;rport
Call-ID: 926efd671923742e
CSeq: 2 MESSAGE
Max-Forwards: 70
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INFO
Content-Type: application/im-iscomposing+xml
User-Agent: eyeBeam release 3006o stamp 17551
Content-Length: 161

<?xml version="1.0" encoding="UTF-8"?>

active
60

SIP/2.0 415 Unsupported Media Type
Via: SIP/2.0/UDP 10.0.0.120:9366;branch=z9hG4bK-d87543-647645781-1–d87543-;rport;received=10.0.0.120
From: Joe Schmoesip:4000@mydomain.com;tag=d1059619
To: sip:4002@10.0.0.50;tag=as1fb08db9
Call-ID: 926efd671923742e
CSeq: 2 MESSAGE
User-Agent: IPPBX ITN
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY
Max-Forwards: 70
Content-Length: 0

MESSAGE sip:4002@10.0.0.50 SIP/2.0
To: sip:4002@10.0.0.50
From: Joe Schmoesip:4000@mydomain.com;tag=024f3a66
Via: SIP/2.0/UDP 10.0.0.120:9366;branch=z9hG4bK-d87543-37684964-1–d87543-;rport
Call-ID: ba64cc352630011a
CSeq: 2 MESSAGE
Max-Forwards: 70
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INFO
Content-Type: text/plain
User-Agent: eyeBeam release 3006o stamp 17551
Content-Length: 9
yada yada

SIP/2.0 405 Method Not Allowed
Via: SIP/2.0/UDP 10.0.0.120:9366;branch=z9hG4bK-d87543-37684964-1–d87543-;rport;received=10.0.0.120
From: Joe Schmoesip:4000@mydomain.com;tag=024f3a66
To: sip:4002@10.0.0.50;tag=as3f67570b
Call-ID: ba64cc352630011a
CSeq: 2 MESSAGE
User-Agent: IPPBX ITN
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY
Max-Forwards: 70
Content-Length: 0

Thank you.