I have heard this questions many times from our customers who purchased either Translator Plugin Pro or Translator Plugin Gold software to autmatically translate their blogs in 41 languages. All of them are concerned if Google will penalize their translated pages as duplicate content. So let's find out what Google has to say about this:

What isn't Duplicate Content

Though we do offer a handy translation utility, our algorithms won't view the same article written in English and Spanish as duplicate content.

Source: Official Google Webmaster Central Blog

That should rest the issue once and for all. If you have any further questions on this feel free to comment below or contact me directly on twitter.