There is a good way to deal with people like this, although it is a bit evil.
1. Start telling them wrong things...bad information.
2. Look incredulous when they try to blame you. If you have even a half-decent reputation where you work, nobody will believe them.
Normally it only takes one time, then you don't have to worry about them talking to you anymore. Hope I don't have to do this to Ms. Newbie, but thanks for reminding me.