[Serusers] Sipsak Question

Hi all, I'm having a little trouble with Sipsak when the Sipsak host is separated from the SER proxy by a SIP aware PIX firewall using PAT. I'm running it on a Windows XP machine with cygwin. I'm using "sipsak-0.8.6.exe -T -s sip:960@192.168.100.10". Everything works fine if I bypass the firewall. The problem I seem to have is I think with the UDP port that Sipsak listens for a response on. For instance it sends from a UDP source port of for example 1055 to the SIP destination port of 5060. But it seems that Sipsak is listening on UDP port 1054 (source port -1) for the reply. I'm running Ethereal on the same PC as Sipsak and I see the replies coming back correctly on port 1055. But since Sipsak seems to be listening on port 1054 the application does not see the replies from my SIP proxy. Is there any way to control the port that sipsak listens for replies on and is it actually listening on UDP send port -1 for replies? Thanks, Paul DISCLAIMER The information in this e-mail and its attachments may be confidential. If you are not the intended recipient, you must not read, use or disseminate that information. If you have recieved this e-mail in error, please notify us and destroy it immediately. Whilst we try to eliminate any viruses or other harmful code or device from our emails or attachments, it is your responsibility to protect your system and we do not accept responsibility for any that may remain. We may monitor or access any e-mails sent to us.