I've discovered, that communicating sth to "normal" people isn't more difficult because of programming. But it's sometimes less understandable what somebody is trying to say, when I'm in "strict thinking" mode.

It's the same with switching between natural languages - I've once met foreigner in Poland in place where I wouldn't think he can be. He was talking to me in English for more than a minute before I've recognized that I must mentaly switch to English to understand him :)

I think social contacts are difficult for programmers, because programming does not require listening to anybody.