They are just insecure and need to see signs that you like them otherwise they think you are unfriendly and start to positively dislike you. Also has happened to me all my life. I hate it when they do that but unfortunately I do the same to others. If they don't affirm me and constantly show pleasure at seeing me, I think they don't like me, and I begin to get defensively bitter towards them.
At my current workplace though, the people are generally nice especially the girl I work most with. She doesn't seem very judgmental. At first, I think she responded badly to my coldness because there was a time she would talk to me as if she didn't like me and never looked my direction. I remember it was after a time that I had had my sensitive feelings hurt by her and tried to avoid her as much as possible. I noticed that her attitude was different, and I didn't like it... being at odds with someone I work with. Distance is one thing but bad feelings are another. I just tried to put my emotions aside and respond to her words and suggestions open-mindedly, not like I was cold and distant. Nothing especially friendly, just open and professional. She responded the same eventually, and, being someone who I don't have any problems with and who generally seemed to respect other people's opinions, I felt comfortable to say some things in the course of business conversations that just sprang to mind, something cute or silly. It only happens sometimes, but it is at my comfort level. And she has responded well and is nice to me. We don't chat like ever. But we are on good terms. It has worked out well.
I think that what you need to do is something to show you have no problem with them at least.
And if they are not like my coworker, but are positively bitter or rude, then that is just unfortunate, and maybe they are not worth it. I d on't know.