[SR-Users] [kamailio 3.1.2] timer issue

Hi Daniel we've installed kamailio 3.1.2 but we have a problem in some type of calls towards IVR machine : an INVITE is replied after a few seconds by 183 session progress starting from that 183, the caller hears a (waiting) message and can choose between several options by sending DTMF tones, like voicemail consulting. the the 183 is sent by far end at 1min interval during the waiting. all 183 are forwarded to the caller the waiting time can last long, after which a human operator answers the call and a 200 ok is replied. but i noticed that after receiving a total of 3 183 session progress, (so 2mins from initial INVITE), then 1 more minute, kamailio sends a 408 timeout to the caller and cancel towards callee. so the calls is hanged up after 3 mins, that means the caller can't wait more than 3mins. i already tried all timers like fr_timer, fr_inv_timer, max_inv_lifetime, restart_fr_on_each_reply... but long waiting calls are automatically hanged up at 3mins. i read an old post at http://www.mail-archive.com/users@lists.kamailio.org/msg04711.html in which you send a patch to apply i'd like to know if you have a clue to this problem. do you have a same patch for 3.1.2 ? thank you very much best regards