B.G.
i don't know what to do, either. My son just started (this week) to send himself to bed when he gets angry with me - "i'm going to bed!!!" he says. and i say "fine!!! just do that!!!" it gets him to settle down and come down later. I used to have to argue with him to go up to his room when he was angry, but i sorta like this better :) lol
good luck - i am hoping it's just a phase...
bgersper