As reported on ekiga-list [1], the user has set up siproxd as the outbound proxy, and the provider is using some other. Thus incoming INVITEs come with a quite a route set:

2010/11/25 07:41:55.793   0:10.694      Opal Liste...0xb6c9ab70 SIP     PDU received: rem=udp$192.168.11.1:5060,local=udp$192.168.11.177:5060,if=192.168.11.177%eth0
INVITE sip:foo@192.168.11.177 SIP/2.0
[..]
Contact: <sip:bar@74.125.46.80:24000>
[..]
Record-Route: <sip:siproxd@192.168.11.1:5060;lr>
Record-Route: <sip:198.65.166.131;lr;ftag=1370489315>
Record-Route: <sip:198.65.166.131;lr;ftag=1370489315>
Record-Route: <sip:74.125.46.80:24000;lr=on>

The user accepts the call, but (likely due to a bug in siproxd) never receives ACK to it's 200 OK, and Ekiga sends BYE to terminate the call. However the route set established for the dialog seems to be ignored and outbound proxy is used instead:

BYE sip:bar@74.125.46.80:24000 SIP/2.0
Route: <sip:lechner-proxy:5060;lr>
[..]


By my understanding of RFC 3261, 200 OK establishes a dialog even if no ACK is received, and the BYE should use the route set from the dialog.

Thanks

[1] http://mail.gnome.org/archives/ekiga-list/2010-November/msg00087.html