there is a script somewhere floating around on the internet to do it. you are supposed to leave it checked but in the background it unchecked itself when you shut down.
i didn't do it because i'm always afraid of using terminal, espc. cause i don't know how to "reverse" the script to make it default.
but if you search google it comes up pretty quick i'm sure, or someone else can chime in who has done it already. 🙂