(gdb) bt
#0  0xb7f2a410 in ?? ()
#1  0xb671668c in ?? ()
#2  0x00000006 in ?? ()
#3  0x00002767 in ?? ()
#4  0xb7d8a811 in raise () from /lib/tls/i686/cmov/libc.so.6
#5  0xb7d8bfb9 in abort () from /lib/tls/i686/cmov/libc.so.6
#6  0xb7285910 in fatal (string=0xb72f8ccc "Unlock when not locked")
    at ftl_unix.c:38
#7  0xb72bc3b2 in imap_send (stream=0xb7b891d0, cmd=0xb7359f36 "SEARCH", 
    args=0xb6716d00) at imap4r1.c:3115
#8  0xb72bf4c2 in imap_search (stream=0xb7b891d0, charset=0x0, pgm=0xb62020c0, 
    flags=0) at imap4r1.c:2029
#9  0xb729235e in mail_search_full (stream=0xb7b891d0, charset=0x0, 
    pgm=0xb62020c0, flags=0) at mail.c:2351
#10 0xb726bf06 in messagecount (context=0xb6717305 "MyPBX", 
    mailbox=0xb6717300 "3200", folder=0xb72f36eb "Old") at app_voicemail.c:2452
#11 0xb726c287 in inboxcount (mailbox_context=0xb7bae508 "3200@MyPBX", 
    newmsgs=0xb671837c, oldmsgs=0xb6718378) at app_voicemail.c:2517
#12 0x0805e253 in ast_app_inboxcount (mailbox=0xb7bae508 "3200@MyPBX", 
    newmsgs=0xb671837c, oldmsgs=0xb6718378) at app.c:190
#13 0xb676239f in sip_send_mwi_to_peer (peer=0xb7badf18) at chan_sip.c:15209
#14 0xb6762faf in do_monitor (data=0x0) at chan_sip.c:15412
#15 0x0810f098 in dummy_start (data=0xb7b669f8) at utils.c:806
#16 0xb7f12240 in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#17 0xb7e2d4ae in clone () from /lib/tls/i686/cmov/libc.so.6