Auto-poweroff on old laptops can be a bit of a problem getting it to work. You'll need to look for the right ACPI settings.
You might want to try booting it with the following as kernel parameter:
And if this breaksaccess to the USB-ports, as it does on my old machine, try this:
I don't know about the light version though. And I don't guarantee it'll work. But it might be worth your time to try.
Do you know how to pass parameters to the kernel during boot?? 'cuz I have no idea how to do that on VL-light
Otherwise just edit lilo.conf and don't forget to run 'lilo -v' afterwards :p