I have distinct problem with giving and taking complements. Logically, I know that it is simply an effort to be nice and to show some awareness of my existence. But always in the back of my mind, especially in the case of complementing someones features, I just feel as though you sound like a big game hunter describing what would look good on their wall or a psycho murderer with a strange fetish. Totally irrational, I know, but nonetheless prevalent. Also I have grown averse to hugs. It might have had something to do with a friend of mine who freaks out when one gave her one and I adopted her manner out of respect, but now its internalized. This perfect storm of phobias makes it that much harder to get along with people, let alone work towards getting a girlfriend. =p
I also agree with almighty aardvark, I become unusually uncomfortable in one on one conversations, as though I feel that I will run out of content in such a way that they resent me, or that something is expected of me. As a result, I think I come off cold and curt, making excuses not to greet my friends, and when I do break the ice, I try to be as brief as possible.