[SR-Users] path use_received not working?

Hello, I have a kamailio proxy in front of FreeSWITCH. Whenever FreeSWITCH initiates the dialog (e.g. sends an INVITE), kamailio doesn't use the 'received' parameter and it forwards to the RFC1918 IP address. The initial INVITE from FreeSWITCH has the following headers: To: <sip:1001@192.168.1.200:5063> Route: <sip:1.2.3.4>;lr;received=sip:5.6.7.8:5063 Where 1.2.3.4 is the kamailio public IP and5.6.7.8 is the public IP of the UAC behind NAT. I have modparam("path", "use_received", 1) in my config file and to my understanding that should be sufficient to route to the proper IP, but kamailio keeps sending INVITEs to 192.168.1.200. Can anyone tell me what am I missing? Thanks! Kind regards, Iskren