Bipolar Coworker

I need help/advise/suggestions!
I recently was hired by a small telecommunications vendor company... I love my job and I'm good at it. My problem -- the coworker that helped me land this job is also my biggest problem!

We met over 20 years ago while I was working on my Masters and then recently while I was working with my last company. We ran into each other while I was networking with the owner of her company & because her business was closely associated with my field, we began working together for business opportunities.

I am a very strong, confident woman. I have worked hard to get to where I am both professionally and personally. I do not doubt myself.

My friend/coworker is very insecure, controlling, and does not like to make mistakes. She very much enjoys directing/leading teams; however, what I'm discovering is she does not know her product which makes her directions unclear, incorrect and creates a lot of work for others.

My first experience with her bipolar personality showed up the first week I went to work. She decided to take vacation that week. During my work week, she called me at least 5-7 times a day wanting to know "what I was doing or what was so and so doing." If I did not answer my phone when she called, she would have the receptionist locate me. I found this behavior very odd.

Upon her return from vacation, she was very upset that my manager had set up a temporary desk for me to work. She expressed her comments directed at me by saying, "they never did anything like this for me when I began work here." "Don't worry, it won't always be like this, they'll forget you." I need to mention that she made it clear that when she began her employment with this company that she would be working from home; she did not want to report to the office. My manager wants me to work at the office.

From then on, she would take over my desk whenever she was in town. Having not ever encountered something like this before nor did I want to start an issue, I did not do or say say anything to her.

At that time, we got along pretty good; however, she did talk to me a lot about why so and so coworker did not return her calls/emails; why did so and so not do this or that which she had requested; or why did so and so keep her out of the loop on this project. I listened to her concerns and tried to coach her on ways to make the situations better. I also tutored her on products/processes that she did not know about or needed to learn. I did this hoping it would make her feel more secure about herself and her position.

During this time she tried to involve me by going to coworkers on her behalf to discuss these issues. She also tried to persuade me to go to our manager about issues she was either having with him or our coworkers. That's when I drew the line and simply said, "I will not do that...it is inappropriate and I do not feel comfortable doing that. If you have an issue with anyone, you should take care of it yourself." She could not believe that I would not help her in that way and inferred that I was not being a team player.

Another situation occurred, one Friday afternoon while she, I and a coworker were discussing a customer solution. All of a sudden, she starts yelling, "Why do you treat me like this. I am not stupid. You all just ignore me like I'm not here, etc." I got scared and didn't know what to say. My coworker acted like nothing had happened. The only thing I thought to do was to touch her hand and say, "calm down." She threw my hand off and then began throwing paper and her work things on the floor. I then left the room because it upset me so. Later when she discussed it with me, she laughed and said to me, "nothing ever bothers you." I could not believe my ears!

She called me over the weekend to apologize; however, that did not make me feel any better. On the following Monday, I went to my manager and explained the situation stating to him that I was not talking about her; I simply needed some advise. I described the Friday outburst by stating this was the second time she had erupted like this and I wanted to know what to do. Unfortunately, all he did was listen and said he really did not know why she did that nor what I could do. He said that he had noticed how insecure she was, but he was also confused as to why she did not know the product or processes since she had been with his company for over a year. I had only been there at that time less than 1 month.

There have been more incidents like this. I will not bore you guys with the details. But the last one occurred when we were away at training. We had overslept for the last day of training because she did not set the alarm clock. When we both awoke, she wanted to take her shower first; however, she made 3 phone calls, pulled out her outfit, then packed some things all before she got in to the shower. Needless to say I was last and she was waiting on me. She impatiently sat tapping her legs, then my phone rang...it was my manager. I took the phone call -- there were some issues he needed to discuss with me. During my call, she repeatedly make comments making it difficult to hear him.
Afterward she said, "I don't know why he called you. He knew we have to get to class. Now we're really be late. I can't believe it. It's so rude to be late. It puts the instructor in an awkward situation." I responded by saying, "I don't want to make you late. Why don't you go on down. I'll follow in a bit." She repeated these things over and over until I got mad. I responded, "there is nothing stopping you from going to the class. I can take care of myself. I don't mind walking into the class late. This situation is no one's fault and I cannot hurry any faster."

Needless to say she did not like my reply. She said she was waiting on me for us to take our luggage to the car. I stated, "I'll leave mine with the front desk. It's no big deal. You go on ahead & I'll catch up." She said "why do you want to do that?" I said so you don't have to wait on me. With that I took my stuff and headed out the door to the elevator. She got very angry at me because she had to pull the luggage cart by herself. When she got into the elevator she said I was acting like a child and started yelling at me. I said "do not yell at me," twice. Then she said "you can find your own way home." She had driven to the training class. I did not say anything to her after that!

Again after this flare up, she went back to being nice, with a slight cold shoulder. I simply ignored it and acted like nothing had happened. However, during our drive home, I was talking with my husband on the phone, she said, I want to talk with him and took it. She proceeded to tell him about our disagreement, not in details, but to let him know we had an argument! I thought this very odd and inappropriate!

I'm really at a loss here. I have never run across an adult who acts like this in the workplace. I have encountered these people socially, but once I find them out, I try not to associate with them again.

Can anyone help me? I do not know what to do or what to say to this person when she acts like a child bully. She really upsets me by her inappropriate behavior and it appears she has been doing this for a very long time both professionally and personally with her family and friends.

My concern now is her latest tactic -- intimidation and bullying with her words. I am not a passive person. Those who know me know I speak my mind. But in this situation, I do not know what to say simply because she makes me angry with her actions and words and I get emotional. I am trying my best not to react or say anything because I know it will do no good. My goal has been to try and get along with her so that we have a professional work relationship but I do not think this is working.

Any suggestions?
I could really use some help!