Just a quick technical aside on the whole virgins debate -- it's not clear it is a mistranslation by any means. The Septuagint has παρθένος, which is virgin - that is the Greek text cited by Matthew, who was writing in Greek. In the (Hebrew) Masoretic text the word is עלמה , that is almah. Problem is almah can mean virgin, or just young woman, but it's not that simple - see
http://en.wikipedia.org/wiki/Almah for a good discussion.
I have checked the Dead Sea Scrolls Great Isaiah Scroll, and yep it reads almah. However the notes for verse 14 make a very convincing argument that virgin in the modern sense was intended -
http://www.ao.net/~fmoeller/7-8.htm#alma - based on the fact that in 285 BCE the translators of the Septuagint chose to use parthenos, virgin, as the term as I note above... if they had believed it meant "young woman" they would have used a different term. SO at least some Jews were reading it this way almost 300 years before the alleged virgin birth.
Hope of interest...
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