(gdb) bt
#0  0xb766a981 in close_mailbox (vms=0xb6ec3788, vmu=0xb6ec3284)
    at app_voicemail.c:4826
#1  0xb7671840 in vm_execmain (chan=0x8224af0, data=0xb6eca008)
    at app_voicemail.c:6733
#2  0x080b66b4 in pbx_exec (c=0x8224af0, app=0x81d5570, data=0xb6eca008)
    at pbx.c:532
#3  0x080b9afa in pbx_extension_helper (c=0x8224af0, con=0x0,
    context=0x8224c70 "sip-internal", exten=0x8224cc0 "*98", priority=1,
    label=0x0, callerid=0x82257f0 "2400", action=E_SPAWN) at pbx.c:1833
#4  0x080babc8 in ast_spawn_extension (c=0x8224af0,
    context=0x8224c70 "sip-internal", exten=0x8224cc0 "*98", priority=1,
    callerid=0x82257f0 "2400") at pbx.c:2288
#5  0x080bb098 in __ast_pbx_run (c=0x8224af0) at pbx.c:2388
#6  0x080bbdf2 in pbx_thread (data=0x8224af0) at pbx.c:2601
#7  0x080f5741 in dummy_start (data=0x82258c0) at utils.c:545
#8  0xb7f22240 in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#9  0xb7d4d3de in clone () from /lib/tls/i686/cmov/libc.so.6