What is causing my redirect error after I upgraded to latest Nginx on latest Ubuntu?

2013/06/10 19:00:01 [error] 1078#0: *5434041 rewrite or internal redirection cycle while internally redirecting to "/index.html", client: 127.0.0.1, server: localhost, request: "GET / HTTP/1.1", host: "localhost"

I have Ubuntu 13:04 Nginx ISPconfig running multiple websites.