===============================================================
[2011/07/12 17:03:54.706201,  0] lib/fault.c:51(fault_report)
  INTERNAL ERROR: Signal 11 in pid 22965 (3.5.9)
  Please read the Trouble-Shooting section of the Samba3-HOWTO
[2011/07/12 17:03:54.706307,  0] lib/fault.c:53(fault_report)

  From: http://www.samba.org/samba/docs/Samba3-HOWTO.pdf
[2011/07/12 17:03:54.706408,  0] lib/fault.c:54(fault_report)
  ===============================================================
[2011/07/12 17:03:54.706480,  0] lib/util.c:1468(smb_panic)
  PANIC (pid 22965): internal error
[2011/07/12 17:03:54.707634,  0] lib/util.c:1572(log_stack_trace)
  BACKTRACE: 15 stack frames:
   #0 0x1369598 <smb_panic+72> at /usr/local/sbin/smbd
   #1 0x13591ac <dump_core_setup+2092> at /usr/local/sbin/smbd
   #2 0x7fffffffffc4
   #3 0x113a033 <reply_write_and_X+787> at /usr/local/sbin/smbd
   #4 0x1179388 <remove_deferred_open_smb_message+1832> at /usr/local/sbin/smbd
   #5 0x117c012 <chain_reply+1730> at /usr/local/sbin/smbd
   #6 0x117c3fd <chain_reply+2733> at /usr/local/sbin/smbd
   #7 0x137887c <run_events+588> at /usr/local/sbin/smbd
   #8 0x117b7fb <smbd_process+1963> at /usr/local/sbin/smbd
   #9 0x16486ed <main+4669> at /usr/local/sbin/smbd
   #10 0x137887c <run_events+588> at /usr/local/sbin/smbd
   #11 0x1378af2 <event_add_to_select_args+498> at /usr/local/sbin/smbd
   #12 0x1378f51 <_tevent_loop_once+129> at /usr/local/sbin/smbd
   #13 0x16484bb <main+4107> at /usr/local/sbin/smbd
   #14 0x110490e <_start+142> at /usr/local/sbin/smbd
[2011/07/12 17:03:54.708369,  0] lib/fault.c:370(dump_core)
  dumping core in /var/log/samba/cores/smbd

P.S. dump is not created