Hmmm, my sense of DB detaching is the 'cold' isn't a part of it. You can be upbeat and positive in your interactions with her, and you can give her her space pleasantly and cordially w/o being cold.
If she perceives that you're withdrawn and pouting - whether you are or not - it's probably not a good thing. I think the DB stuff says that we should present a happy, confident face to our spouses no matter what we are feeling inside. Maybe a more experienced poster will chime in with a better explanation.
The trouble with having an open mind is that people put things in it.
My sitch - Divorce Busted! http://www.divorcebusting.com/forums/ubbthreads.php?ubb=showflat&Number=1804137#Post1804137