[SR-Users] Kamailio 1.5 stops processing messages

Hi, I'm working with Kamailio 1.5 (rev 5968) and from time to time kamailio freezes and stops processing messages. Kamailio is working only in UDP. I really don't know in which conditions this problem is happening: it happens both in high and low load. Here is a backtrace of one of the UDP working processes when kamailio is frozen (all the other UDP process backtraces look similar) : #0 0xb7fdf410 in ?? () #1 0xbfbfec28 in ?? () #2 0x00000001 in ?? () #3 0xa7392ad0 in ?? () #4 0xb7f3b4ac in sched_yield () from /lib/tls/i686/cmov/libc.so.6 #5 0xb7ba9463 in lock_hash (i=10361) at ../../mem/../fastlock.h:182 #6 0xb7bc4587 in t_lookup_request (p_msg=0x823fc70, leave_new_locked=1) at t_lookup.c:468 #7 0xb7bc54ae in t_newtran (p_msg=0x823fc70) at t_lookup.c:1124 #8 0xb7bb740c in t_relay_to (p_msg=0x823fc70, proxy=0x0, flags=1) at t_funcs.c:212 #9 0xb7bb8f6c in t_replicate (p_msg=0x823fc70, dst=0x817cdf8, flags=1) at t_fwd.c:763 #10 0xb7bc7fce in w_t_replicate (p_msg=0x823fc70, dst=0x817cdf8 "\230ê\030\b\016", flags=0x0) at tm.c:957 #11 0x0805301c in do_action (a=0x818eb20, msg=0x823fc70) at action.c:874 #12 0x080557aa in run_action_list (a=0x818eb20, msg=0x823fc70) at action.c:145 #13 0x08054491 in do_action (a=0x818ec78, msg=0x823fc70) at action.c:746 #14 0x080557aa in run_action_list (a=0x818c940, msg=0x823fc70) at action.c:145 #15 0x08053efb in do_action (a=0x81b38e0, msg=0x823fc70) at action.c:120 #16 0x080557aa in run_action_list (a=0x81b3878, msg=0x823fc70) at action.c:145 #17 0x08054491 in do_action (a=0x81b5f00, msg=0x823fc70) at action.c:746 #18 0x080557aa in run_action_list (a=0x81b5f00, msg=0x823fc70) at action.c:145 #19 0x08054f2d in do_action (a=0x81b5f68, msg=0x823fc70) at action.c:752 #20 0x080557aa in run_action_list (a=0x81b5f68, msg=0x823fc70) at action.c:145 #21 0x08054f2d in do_action (a=0x81b5fd0, msg=0x823fc70) at action.c:752 #22 0x080557aa in run_action_list (a=0x81aefd0, msg=0x823fc70) at action.c:145 #23 0x08053efb in do_action (a=0x818bc08, msg=0x823fc70) at action.c:120 #24 0x080557aa in run_action_list (a=0x8187910, msg=0x823fc70) at action.c:145 #25 0x08055b43 in run_top_route (a=0x8187910, msg=0x823fc70) at action.c:120 #26 0x0808c659 in receive_msg ( buf=0x8158040 "REGISTER sip:xxxxxxxxxxx.com SIP/2.0\r\nFrom: < sip:xxxxxx@xxxxxxxxxxxx.com &lt;sip%3Axxxxxx(a)xxxxxxxxxxxx.com&gt;&gt;;tag=as516fcce2\r\nToce2\r\nTo: <sip:xxxxxxx@xxxxxxxxxxxx.com &lt;sip%3Axxxxxxx(a)xxxxxxxxxxxx.com&gt;&gt;\r\nCall-ID\nCall-ID: 01e4ea8e185c85332ea68874543c810e(a)xxxxxxxxxxxxxx.com\r\nCSeq: 383 REGISTER\r\nVia: SIP"..., len=794, rcv_info=0xbfc004d4) at receive.c:175 #27 0x080c3ea3 in udp_rcv_loop () at udp_server.c:449 #28 0x0806e394 in main (argc=9, argv=0xbfc006b4) at main.c:774 Any idea of what might be happening? Best regards, Santi