I have tried two method:
1,add "acpi=force apm=power_off" to menu.lst
It still can not solve the problem.
Afterwards, I find I disable ACPI which has some functional things about managing the power for bus and others. I have a look at the guide book from
RTAI and find I need enable ACPI.
So today I recompiled the kernel and enable it. Now it's working!!!
About how to disable and enable NetworkManager:
sudo /etc/dbus-1/event.d/26NetworkManagerDispatcher stop/start
sudo /etc/dbus-1/event.d/25NetworkManager stop/start