asterisk users - Sep 2004 - SIP channel stuck after registration

Quick question for the experts: I'm seeing stuck SIP channel(s)
scheduled for destruction stay open. This appears to happen
after (apparently successfully) registering with a SIP peer.

Any ideas where to start digging into this? I'm running today's
CVS, however the problem existed before and does persist.

Thanks,
Kai-Uwe

Example: (registration with iconnecthere.com)

ast1000*CLI> sip show channels
Peer             User/ANR    Call ID      Seq (Tx/Rx)   Format
213.137.73.140   133357xx    1e7ff5217c3  00104/00000   UNKN  (d)
1 active SIP channel(s)

ast1000*CLI> sip show history
1e7ff5217c3dbd3d737b8ddc6ceaf087@192.168.254.250
ast1000*CLI> 
  * SIP Call
1. TxReqRel        REGISTER sip:sipauth.deltathree.com SIP/2.0 / 104 REGISTER
2. Rx              SIP/2.0 100 Trying / 104 REGISTER

However, I seem to be successfully registered:

ast1000*CLI> sip show registry
Host                            Username       Refresh State               
sipauth.deltathree.com:5060     133357xx          1785 Registered 

Also:

ast1000*CLI> sip show channel
1e7ff5217c3dbd3d737b8ddc6ceaf087@192.168.254.250
ast1000*CLI> 
  * SIP Call
  Direction:              Outgoing
  Call-ID:                1e7ff5217c3dbd3d737b8ddc6ceaf087@192.168.254.250
  Our Codec Capability:   22
  Non-Codec Capability:   1
  Their Codec Capability:   0
  Joint Codec Capability:   0
  Format                  UNKN
  Theoretical Address:    213.137.73.140:5060
  Received Address:       213.137.73.173:41796
  NAT Support:            No
  Our Tag:                1275433177
  Their Tag:              
  SIP User agent:         
  Username:               133357xx
  Peername:               133357xx
  Original uri:           sip:sipauth.deltathree.com
  Need Destroy:           1
  Last Message:           
  Promiscuous Redir:      No
  Route:                  N/A
  DTMF Mode:              rfc2833

The Polycom phones have an instant messaging function - any idea what is
required to make it work?

PaulH
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