[Users] missing record-route when using uac_auth()

i am trying to use uac_auth() on CVS-HEAD but somewhere there is a problem with missing record-route headers. the SIP sessions looks like this: client: INVITE openser: SIP/2.0 100 trying openser: SIP/2.0 183 Session progress openser: SIP/2.0 200 Ok (no record-route!) client: ACK (directly - not to openser because of missing rr) so everything is fine until the remote end sends the Ok to OpenSER (which is further relayed to the client). OpenSER doesn't insert a Record-Route header and my client therefore sends the ACK directly to the remote-end instead of sending it to OpenSER. as the remote-end expects the ACKs from OpenSER it ignores them and after sending some further OKs it quits the sessions. when i try the same thing using another destination (which doesn't go through the uac_auth() stuff) it works fine (= rr header is inserted), so i'm not sure if this is a bug in my config or OpenSER. i have put my config online at: http://pastebin.com/614703 the case where it works fine is when dialing a sip-uri. in this case route[3] is called as INVITE handler which calls route[1] to relay the message. the problem occurs when dialing a numeric uri. in this case route[3] calls route[5] which is basically the same as route[1] with the exception of using a uac_auth failure route and a t_relay to a specific destination. any hints about the cause of this problem? bye, /gst