Transsexuals and "passing"

I was reading an article written by a transsexual person (which I unfortunately can't find now to link) that raised a question for me. One issue this individual talked about was that he (born a female, lives as a man, post transition), is neither considered a man or a woman by some people. For instance, he is interested in women. He said that many times women will consider him a lesbian female if he tells them he is transsexual, and say that they aren't gay. But, he said, if he didn't tell them he would feel dishonest.

Many times I have heard men say they absolutely would not want a woman who was born a man.

I am wondering what you guys all think of this. My question is as follows: assuming you were attracted to an individual, would it impact or change how you feel to learn they had been born a different gender? for simplicity let's assume they are Post transition and are fully and completely whatever sex it is you're interested in, physically and mentally.

Eta for sake of argument say you met someone, had coffee or something, and haven't yet had sex. They tell you this before intimacy in view of being open.