asterisk users - Sep 2005 - cvs head and seqno 102 (Critical Response) messages for Cisco 7960

I've being using the same non-nat config for a 7960 for about a year with no
issues.

I have just upgraded cvs head from the 16th of July to todays.

About a minute after I make a call I get the message
 chan_sip.c:1132 retrans_pkt: Maximum retries exceeded on transmission
000b46a0-8661007f-5c457e72-2b0dba2c@192.168.123.20 for seqno 102 (Critical
Response)


I don't get this for other makes of phone I have.

Anyone else had this?

Chris