I think as long as you do have a contract and keep everything in writing, and also save all e-mails, make notes after phone conversations, etc, you should be fine.
Plus, I find a majority of the women on theknot to be unnecessarily nasty. You'd think they'd be the happiest forum on the internet, basking in wedding bliss - doesn't appear to be that way in most of their threads.
I think a big part of some knotties and vendors is their attitude - if you go in with one, you'll get one right back. Be your charming self to this woman, and you'll get a lot more in return.