Who was Quirinius?

I've been memorizing Luke 2:1-21, and every time I recite verse 2 I find myself stumbling over the name Quirinius. It just doesn't trip off the tongue as nicely as Caesar Augustus. How did this guy get in the Bible?, I wondered. So I did what any normal person with a computer does in such cases: I googled him. Well, it turns out alliteration is not the only difficulty here. Google turned up literally thousands of results for Quirinius, henceforth Q (but don't confuse him with this guy). A lot of the stuff I turned up was from people who want to cast doubt on the reliability of the New Testament authors, because, as I learned, there's an apparent discrepancy in Luke's dating of Jesus's birth in relation to the first Roman census and the years when Q was governor of Syria. These people say "aha, here's the smoking gun that proves that the Christmas story is a fairy tale"! This kind of mistake would be out of character for Luke, since he's proved over and over to be a careful and reliable historian. For instance, in Acts, details that he gives regarding places and people of the ancient Roman world, which were once thought to be wrong, have turned out to be accurate based on more recent historical and archaeological research.

Time and further research may prove Luke right in this case too. But, in the meantime, does the fact that we can't resolve this definitively cast doubt on Luke's account of the first Christmas? Indeed of the whole Bible? It doesn't for me. One possible historical inaccuracy doesn't cancel out the hundreds of instances where the Bible has proved to be remarkably accurate. And as New Testament scholar Daniel Wallace points out in a balanced (and very technical) discussion of The Problem of Luke 2:2:

At bottom, our belief in the infallibility and authority of scripture is a faith-stance, just as our belief in the Deity of Christ is a faith-stance. This does not mean that we have no basis! Nor does it mean that we are obligated to solve all problems to our satisfaction before we can believe. As B. B. Warfield argued long ago, we believe in the accuracy of the Bible, first of all, because the biblical writers themselves both held and taught this view. And if we consider the biblical writers to be trustworthy as doctrinal guides, then their doctrine of the Bible must also be trustworthy.