我的discuz放在bbs二级目录中，一级目录放的是wordpress mu程序，我的nginx配置如下：

    log_format  vfcai.com  '$remote_addr - $remote_user [$time_local] "$request" '
             '$status $body_bytes_sent "$http_referer" '
             '"$http_user_agent" $http_x_forwarded_for';


server
    {
        listen       80;
        server_name vfcai.com *.vfcai.com;
        index index.html index.htm index.php default.html default.htm default.php;
        root  /data/wwwroot/vfcai.com;

        include wordpress.conf;
        location ~ .*\.(php|php5)?$
            {
                try_files $uri =404;
                fastcgi_pass  unix:/tmp/php-cgi.sock;
                fastcgi_index index.php;
                include fcgi.conf;
            }

        location ~ .*\.(gif|jpg|jpeg|png|bmp|swf)$
            {
                expires      30d;
            }

        location ~ .*\.(js|css)?$
            {
                expires      12h;
            }

        access_log  /home/wwwlogs/vfcai.com.log  vfcai.com;
    }
server 
{ 
    server_name www.vfcai.com;
    rewrite ^(.*) http://vfcai.com/ permanent; 
}
server
{
    server_name bbs.vfcai.com;
    index index.htm index.html index.php;
    root /data/wwwroot/vfcai.com/bbs/;
    location ~ .*\.(php|php5)?$
    {
        try_files $uri =404;
        fastcgi_pass  unix:/tmp/php-cgi.sock;
        fastcgi_index index.php;
        fastcgi_param  SCRIPT_NAME        /bbs/$fastcgi_script_name;
    }
    location ~ .*\.(gif|jpg|jpeg|png|bmp|swf)$
    {
        expires      30d;
    }

    location ~ .*\.(js|css)?$
    {
        expires      12h;   
    }
}

我通过bbs.vfcai.com访问我的网站的时候会出现index.php的下载，不能正常访问网站，请问下我的nginx配置哪里出错了？