Yeah, I was thinking that when I first read that part. There is no reference in the films whatsoever to Anakin being immaculately concieved. And it wouldn't make sense if there was as SW usually only deals with a fairly black and white morality and never had any mention of sins or children being bore stained with the sins of their fathers. The only mention of his birth at all is when his mom says that there was no father and that she couldn't explain how she got pregnant. Hmm, and if you really think about it, that isn't even to say that he was born of a virgin, since we don't know if his mom was actually a virgin or not, it just means he was concieved asexually...