Have you ever watched "The Dog Whisperer", Gina? He has some great ideas on how to handle this sort of thing. Gayle was right in suggesting pack behavior and making yourself the leader and the ways she suggested will work. Also, make sure that you walk through a doorway first, because YOU are the leader. I think that there's a book out by Ceaser Millan.
http://www.cesarmillaninc.com/dogwhisperer/
You might want to watch some of his videos and get an idea of what he does.
http://channel.nationalgeographic.co.../dog-whisperer