I've heard that many Aspies give off an "uncanny valley" vibe sometimes. Like, they may seem normal enough, do all the right things, and yet there's just something that still feels a bit off about them. Personally, I think it's likely more a facial expression/voice intonation/body movement thing. Sometimes when I'm polite with people I'm not particularly familiar or comfortable with, I tend to keep myself very composed and controlled, often smiling or nodding along to whatever they say. Apparently this has rubbed some people as being almost robotic, since some part of them can tell that I'm not acting in a totally "natural" way. Of course, I ease up and act my more normal self as I get to know them better, lessening the robotic effect.

Maybe it's a bit of a similar thing with you too?