403使用nginx禁止wordpress索引,其余页面工作正常

我正在一个新的EC2实例上设置我的博客,因为当前托管它的服务器上的一个站点是DDoSed.
我在使用nginx时遇到了一些麻烦,因为我可以看到所有页面都很好但是索引上有403,或者看到索引但页面上有404(取决于我使用的配置)

这是我的nginx配置：

server {
    listen       80;

    server_name  www.test.com;
    server_name  test.com;
    root /www/blog;

    include conf.d/wordpress/simple.conf;
}

而simple.conf：

location = /favicon.ico {
            log_not_found off;
            access_log off;
    }

    location = /robots.txt {
            allow all;
            log_not_found off;
            access_log off;
    }

    location / {
            # This is cool because no php is touched for static content. 
            # include the "?$args" part so non-default permalinks doesn't break when using query string
            try_files $uri $uri/ /index.php?$args;
    }

    location ~ .php${
            #NOTE: You should have "cgi.fix_pathinfo = 0;" in php.ini
            include fastcgi.conf;
            fastcgi_intercept_errors on;
            fastcgi_pass unix:/var/run/php-fpm/php-fpm.sock;
    }

    location ~* .(js|css|png|jpg|jpeg|gif|ico)${
            expires max;
            log_not_found off;
    }

如果我改变了try_files $uri $uri / /index.php?$args;索引index.php,首页将正常工作,其余的将是404.如果我这样离开,首页是403.

这是错误日志：

2013/08/07 19:19:41 [error] 25333#0: *1 directory index of "/www/blog/" is forbidden,client: 64.129.X.X,server: test.com,request: "GET / HTTP/1.1",host: "www.test.com"

该目录在nginx用户上是755：

drwxr-xr-x 6 nginx nginx  4096 Aug  7 18:42 blog

有什么明显的我做错了吗？

谢谢 ！