[SR-Users] Multi-homed Kamailio Modifies ACK

Hi all, I'm having a scenario where I'm sending call to CISCO IAD2431. The call establishes with 200OK from CISCO and Kamailio sends back modified ACK. Cisco at this points gives out an error and sends 200OK again, Kamailio replies with ACK, and this cycle goes on until the call drops. Here is the error from CISCO: Failed FROM/TO Request check old_from: "Test Phone" <sip:+14432232221@192.168.1.106>;tag=as370915fc old_to: <sip:+14444812211@sip.iamip.com:5041>;tag=9FEC572E-100F new_from: "Test Phone" <sip:+14432232221@192.168.1.106>;tag=as370915fc new_to: <sip:+14444812211@192.168.1.244:5041>;tag=9FE I've #auto_aliases=no and, listen=udp:44.33.22.11:5041 listen=udp:192.168.1.244:5041 Kamailio sends INVITE through the Public IP to the CISCO gw, but decides to change the ACK header. Any advise please. Best Regards, Sammy.