We've had two different SC polls from ARG, both of which had Clinton leading, but that's it, as far as I can recall. The only other SC Dem. poll I can remember is the one from Elon University, which was a poll of five Southern states. If you look at their internals, the subsample from SC had Clinton and Obama tied for the lead, with a huge number of undecideds. But the number of respondents from each state was so small that you should probably just ignore the state subsamples.
Oh wait, sorry, I was thinking of North Carolina polls. You're right, we haven't seen many South Carolina polls.