[Serusers] can't login using MSN messenger 4.6

[Andy Singh]

Hi All

I've just installed ser server...seems to running ok, but when i try to log
in via MSN messenger, it doesn't connect. ngrep shows this
[root at jmay-csx root]# ngrep  -n 5060 -d eth0 andy
interface: eth0 (156.151.96.0/255.255.254.0)
match: andy
############################################################################
############################################################################
#########################################################
U 156.151.96.136:1299 -> 156.151.97.201:5060
  REGISTER sip:portal.com SIP/2.0..Via: SIP/2.0/UDP 156.151.96
  .136:9924..Max-Forwards: 70..From: <sip:andy at portal.com>;tag
  =e7de21b1a54048f596a97a803e62a092;epid=3e95aa3126..To: <sip:
  andy at portal.com>..Call-ID: 907cde0319b64cba8b1dd03f75ce90a9@
  156.151.96.136..CSeq: 1 REGISTER..Contact: <sip:156.151.96.1
  36:9924>;methods="INVITE, MESSAGE, INFO, SUBSCRIBE, OPTIONS,
   BYE, CANCEL, NOTIFY, ACK, REFER"..User-Agent: RTC/1.2.4949.
  .Event: registration..Allow-Events: presence..Content-Length
  : 0....
#########
U 156.151.97.201:5060 -> 156.151.32.148:5060
  REGISTER sip:portal.com SIP/2.0..Record-Route: <sip:156.151.
  97.201;ftag=e7de21b1a54048f596a97a803e62a092;lr=on>..Via: SI
  P/2.0/UDP 156.151.97.201;branch=z9hG4bKae7d.a118d8e6.0..Via:
   SIP/2.0/UDP 156.151.96.136:9924..Max-Forwards: 69..From: <s
  ip:andy at portal.com>;tag=e7de21b1a54048f596a97a803e62a092;epi
  d=3e95aa3126..To: <sip:andy at portal.com>..Call-ID: 907cde0319
  b64cba8b1dd03f75ce90a9 at 156.151.96.136..CSeq: 1 REGISTER..Con
  tact: <sip:156.151.96.136:9924>;methods="INVITE, MESSAGE, IN
  FO, SUBSCRIBE, OPTIONS, BYE, CANCEL, NOTIFY, ACK, REFER"..Us
  er-Agent: RTC/1.2.4949..Event: registration..Allow-Events: p
  resence..Content-Length: 0....
############################################################################
#####
U 156.151.96.136:1299 -> 156.151.97.201:5060
  REGISTER sip:portal.com SIP/2.0..Via: SIP/2.0/UDP 156.151.96
  .136:9924..Max-Forwards: 70..From: <sip:andy at portal.com>;tag
  =e7de21b1a54048f596a97a803e62a092;epid=3e95aa3126..To: <sip:
  andy at portal.com>..Call-ID: 907cde0319b64cba8b1dd03f75ce90a9@
  156.151.96.136..CSeq: 1 REGISTER..Contact: <sip:156.151.96.1
  36:9924>;methods="INVITE, MESSAGE, INFO, SUBSCRIBE, OPTIONS,
   BYE, CANCEL, NOTIFY, ACK, REFER"..User-Agent: RTC/1.2.4949.
  .Event: registration..Allow-Events: presence..Content-Length
  : 0....
  resence..Content-Length: 0....

what else can i look at...what might be the cause.

thaks
Andy