You've noticed that. The clowns at Real Clear Politics won't show polls that Gingrich is ahead or are slow on the uptake. It is by design.
The latest omission is the ARG Mississippi poll with Newt clearly ahead.
Some polls don’t get picked up by Real Clear Politics. I don’t know why.
Here are four for AL since Mar. 1,: http://www.realclearpolitics.com/epolls/2012/president/al/alabama_republican_presidential_primary-1775.html#polls
MS is definetly short on polling data at Real Clear Politics.