This whole eye-contact-thing is one of my bigger issues, before I got diagnosed, I hardly looked anyone into the eyes, or heck, the whole face (which is why I recognize people by voice, body posture and build). Now, I have little to no experience with girls in the matter of relationships, but I have noticed that lack of eye contact seems to alienate girls when it comes to attracting them in a romantic fashion. I try to force myself to make eye-contact with people I talk to, but it is still a long way till I find the balance, since I now tend to stare, and both guys and especially girls told me that that made them feel very, very uncomfortable, which I believe them, no question. It must be really awkward if you are having conversation with someone and he is staring at you as if he was going to shoot lasers out of his eyes any second now.
I guess any trait that comes with Asperger's syndrome can be an attractionkiller all by itself. If you have very narrow focused interests (like I do), it better be something that impresses the ladies, but chances are that most of the time, it isn't (which I think would be my greatest asset, since I'm extremely into martial arts, but talking about it is as boring as anything for someone who is not involved). And I bet women are not attracted by some guy that starts talking about astro-physics and never ever stops, just goes on and on and on. I know I used to be like that, talking about things that concerned my interests. Now, when I am at a party or with friends, I usually try to stay quiet and keep a distance to most conversations, and when someone does start talking to me, I'm always thinking to myself: "Please don't tempt me, please don't tempt me!" In a related matter, many Aspies tend to speak monotone (which I don't), and / or very formal, like they would write an essay (which I do, as you can plainly see. The way I'm writing these things here are exactly how I would describe these things verbally, and I have been talking like that since the age of six or seven.)
Also, it doesn't help that we tend to say insensitive things at inappropriate times. I remember a situation when I was introduced to a group of a girl and two guys, both of them seemed to really have the hots for her (but were waaaay out of her league both intellectually and attractive wise, and I have to say she was really cute and smart), and during conversation where they were fooling around a little, they said something like "You know, she is very special to us both!", to which I replied: "Maybe it's because she has a vagina!". A friend had to tell me later that this cunning remark of mine made them all three terribly mad, the guys because I hit a nerve there, and the girl... well, no explanation needed.
Without wanting to write too much now, the fact that people with Asperger's are extremely easy to irritate and may seem childish if things turn out in a different way than they expected. Seriously, as a woman seeking a mature partner that may father her children, would you consider someone a suitable partner that can fly into a rage for no apparent reason over things no normal person would even get upset about? This, again, is one of the traits that shows in me the most. I do consider myself to have a rather high amount of self-control, but to sum it up, I tend to get along with small children very well, because I have the emotional maturity of a 10-year old.