> Are you running it when it happens ?
> If to, try to reproduce this in text mode, on vt0 (ctrl-alt-f1 to switch
> console). I suspect the machine panics and fall in debugger.
> At the db> prompt, type tr and report us this, along with the panic message.
> 
hi, I get some message by using gdb. I hope this will be helpful. :)
(gdb) target kcore /var/crash/netbsd.3.core
#0  0xc0271d08 in db_last_command ()
(gdb) bt
#0  0xc0271d08 in db_last_command ()
#1  0x2da000 in ?? ()
#2  0xc01df7b3 in cpu_reboot (howto=260, bootstr=0x0)
    at ../../../../arch/i386/i386/machdep.c:1379
#3  0xc0110034 in db_sifting_cmd (addr=1, have_addr=0, count=-1071617727, 
    omodif=0xc02d9c9c " §§ÀÜ001") at ../../../../ddb/db_command.c:657
#4  0xc010fce4 in db_command (last_cmdp=0xc0271d08, cmd_table=0xc022b8bc)
    at ../../../../ddb/db_command.c:319
#5  0xc010feaa in db_command_loop () at ../../../../ddb/db_command.c:555
#6  0xc0112f66 in db_trap (type=1, code=0) at ../../../../ddb/db_trap.c:88
#7  0xc01dcf7a in kdb_trap (type=1, code=0, regs=0xc02d9dc8)
    at ../../../../arch/i386/i386/db_interface.c:119
#8  0xc01e4848 in trap (frame={tf_es = 16, tf_ds = 16, tf_edi = -1071052768, 
      tf_esi = -1070752168, tf_ebp = -1070752256, tf_ebx = -1069214464, 
      tf_edx = 32, tf_ecx = 62496, tf_eax = 62496, tf_trapno = 1, tf_err = 0, 
      tf_eip = -1071787980, tf_cs = 8, tf_eflags = 514, tf_esp = -1070752240, 
      tf_ss = -1071605776, tf_vm86_es = -1069214464, tf_vm86_ds = -1069162486, 
      tf_vm86_fs = -1070752180, tf_vm86_gs = -1071605351})
    at ../../../../arch/i386/i386/trap.c:212
#9  0xc0100cb9 in calltrap ()
#10 0xc02097f0 in internal_command (sc=0xc0451500, type=0xc02d9e58, 
    ksym=62496, ksym2=27) at ../../../../dev/wscons/wskbd.c:1337
#11 0xc0209999 in wskbd_translate (id=0xc0290820, type=2, value=1)
    at ../../../../dev/wscons/wskbd.c:1425
#12 0xc02089bb in wskbd_input (dev=0xc0451500, type=2, value=1)
    at ../../../../dev/wscons/wskbd.c:581
#13 0xc020c332 in pckbd_input (vsc=0xc0455800, data=1)
    at ../../../../dev/pckbc/pckbd.c:554
#14 0xc010a0bb in pckbcintr (vsc=0xc044ba80) at ../../../../dev/ic/pckbc.c:931
#15 0xc0100f58 in Xintr1 ()
(gdb)