Mindfulness doesn't mean you turn yourself into a doormat. It can actually help when you feel you have to confront someone.

Here's a very good book I read about this, if anyone here is interested. It's about time I re-read it myself: Radical Acceptance, Embracing Your Life with the Heart of a Buddha by Tara Brach PhD. It can be found here:

UK
http://www.amazon.co.uk/Radical-Acc...ks&qid=1189750476&sr=1-1

US
http://www.amazon.com/Radical-Accep...ks&qid=1189750572&sr=1-1