Can't say I'm really surprised. After all, Newt is from Georgia, which as you probably know, shares a rather long border with South Carolina. Plus the other two leading candidates are from northern states, one is Mormon, the other Catholic. Neither of them have anything about them that really resonates with southerners while Newt is a southerner. It would surprise me if he didn't do well in the south.
ETA: I'm not saying it's a good thing, just that it doesn't surprise me.