Looks like cyphastrea to me. I'm basing my guess off a frag I got from Melissa. The piece I have is different colors, but the polyps are the same. Here is a link to a differenty kind a cyphastrea:
http://www.reeffarmers.com/limitedcyphastreaocellina.htm">http://www.reeffarmers.com/limitedcyphastreaocellina.htm</a>
I could be completely wrong, but thought I'd share my 2 cents.
-Andy