The same thing happened to my blog about two months ago. I can’t remember who I corresponded with, but they said it was spam related. Which was wrong as rain because I’ve never done that. I told them I thought it was because I had so many anti-Obama posts. They replied only that they would work to fix the problem. They did fix it about 3 weeks later. And everything was back to normal. I did some research then and found there were many MANY other instances of where bloggers claimed to have been blacklisted. My advice...complain like hell.