I have question that relates to a fellow co-worker. We once had a very nice relationship where we could talk about stuff, and recently it has changed for the worse. I have ponder why it has gone this way for a while and now we are at the point were we do not speak to each other, or if I speak, her response is subtle or forced. I wonder if I should confront her and see what is problem, or should I just leave it alone? I am not a person who likes conflict or tension and feel if someone is not speaking to me then I should do the same. I realize that is not the attitude to take, but I am not sure what else I can do. It makes it even worse because she works close to me.
If this disagreement is like most between men and women, then it is probably along the lines where she feels the problem is obvious and the reason you aren't apologizing is because you're trying to hurt her. Meanwhile, your only clue is that she is not speaking, so you don't know how to fix something you can't define.
The best thing to do is simply and politely ask. "I know I'm a bit dense at times, but it has finally dawned on me that you're not speaking to me. The problem is that I'm not clever enough to work out why. Is there something that I have done or not done that has offended you?" Try to word your question so that you are not, even indirectly, stating that she is the one with the problem. Then sit back and listen. She might continue to ignore you, she might verbally take your head off, but then she might tell you what is wrong.
No matter how she responds, remind yourself that how she responded to a polite question is her choice. It was your choice to bring the matter to the forefront. If she lets you know loudly or quietly, at least you will have something to consider and work on. But either way, prepare yourself to not reply in anger. You wanted to know, and likely what you will learn isn't going to be pleasant to hear. "So then, my beloved brethren, let every man be swift to hear, slow to speak, slow to wrath; for the wrath of man does not produce the righteousness of God" (James 1:19-20).
If you get the silent treatment, then just shrug it off as something out of your control. You can't fix everything. At least she knows you are interested and perhaps she'll tell you later when she is ready to speak. She might simply be putting it off because she doesn't like conflicts either and she is afraid to bring the matter up for fear that she or you might lose your temper.