Paidion I really don't mean any disrespect, please don't be saying "your Bible," I don't accept any one translation as infallibly inspired because we don't have the autographs, and so it just sounds silly for me, and I respect any sincere attempt at translation (I have hundreds as I'm sure you do also).
I'm glad you brought this post up, will be nice to get into. First off, it's been a little while since I've studied up so I will need time to get something together; please don't think because of that I'm conceding or running away. I'd like to just lay out some basic facts so you know where I stand about it. First off, I have a very high view of the LXX, and some of the Greek is simply beautiful. The different books appear to have different histories at times, and written in somewhat different styles. You can easily research all that on your own. The story of the 70 is probably just made up to make the Jews feel less insecure about using a translation, you know how people get around religious books, trying to find a perfection in the flesh. We can clearly, at the outset, say that the Greek LXX/Septuagint/OT is not source material (was not the original language the books where written in). There's several ways textual critics determine something like that, and I won't pretend to be an expert. But if we believe the Biblical narrative itself, we will see the place in history and evolution of the language from Phonecian to proto-Hebrew and onwards, and how the history and peculiar language so often fits exactly into the text, even sometimes to the very way the Hebrew words sounded themselves. I'm sure you agree on that point, I'm not trying to be condescending just cover the bases. So the question is what Hebrew strains of manuscripts did we have before the Masoretic became mainstream and more effort was put into preserving accuracy. We can't know that for certain, just look at what we have and how diligent those Jews were.
So the LXX has two main values, one is it often represents an older stream of Hebrew (that often agrees with the DSS!), and two is, it was almost always used by the NT authors due to their cultural context, and so sometimes fit in really well with the NT language and doctrine. I have no problem with believing God could bring in even a mistranslated or oddly translated text and make it inspired by the use of the NT authors, but people's method and system of determining inspiration is widely varied and often an intense belief for them, so I respect whatever systems people have in that regard. Now if the LXX merely has a deviant reading, we are perfectly well justified in thinking it may represent another Hebrew strain of manuscripts (and yes, a more correct one!), however if we can theoretically find a reason the Hebrew would have been difficult to understand or mistranslated, then I don't think we are necessarily justified in assuming further causes without a good reason. Many of the errors in the LXX are when the Hebrew is most obscure or difficult, or when the Hebrew idiom sounds very unnatural to the Greek ear, just as those idioms are often changed in the English we have today. (Also the LXX is not one united book, but many books written at different times, that can even disagree with one another like any manuscript strain.) So having established the LXX is a real, albeit excellent, translation of another language, I'll try to find time to find some easily understood discrepancies that don't need an outside explanation. If anyone else wants to chime in or help, or correct my poor knowledge of things, I welcome that.
And for those interested we have some nice English translations, Brenton's is great, NETS, the Apostle's Bible (really excellent), and others.
To broaden a bit one's understanding of some factors involved in moving one language to another check out a chapter by the expert Emanuel Tov on some factors in moving Hebrew into Greek:
http://www.emanueltov.info/docs/papers/ ... d.1999.pdf
For Alfred Edersheim's opinion on the LXX (quite a bit biased but) as well as some comparisons to Paul's quotes (most don't seem that big a difference for me personally) and a few problems texts (the Isa. 9 has some silly logic in it):
http://www.jesuswordsonly.com/books/451 ... ation.html
I'll attempt when I can get some time to find a few of the best examples of where the Greek translators simply did not translate the Hebrew correctly.