The accountant at our small company that I have worked at for about 3 years was friendly to me at first, but now finds it necessary to make references to my "stupidity" or "dumb" actions. Often times in front of other co-workers. She doesn't do this to anyone else that I know of; however, she often times makes comments about other select co-workers abilities. She has power issues; she is very good at her job, but obviously has issues in relating to others.
Fortunately, I have a strong personality and am confident in my abilities. I really have had enough though, and am going to tactfully tell her to back off or I will file an official complaint. Don't know if it will do any good, but it should send a message to her that she is not going to continue the abuse and get satisfaction any longer!