Nginx serves files without extension too slow [closed]

Question

I'm removing extensions from uploaded files in my CMS. If the file is an image, the thumbnail has JPG extension but the original file is extensionless. Example:

http://gazi.edu.tr/upload/26/2012/10/9/2f97e51581606b2dd606faf82cd4ce9ff784e87f-small.jpg
http://gazi.edu.tr/upload/26/2012/10/9/2f97e51581606b2dd606faf82cd4ce9ff784e87f

The problem is, nginx serves the thumbnail very fast. But the original file is waiting for minutes.

Here is my full config file:

server {
        #listen   80; ## listen for ipv4; this line is default and implied
        #listen   [::]:80 default ipv6only=on; ## listen for ipv6

        root /usr/share/nginx/www/public;
        index index.html index.php index.htm;

        # Make site accessible from http://localhost/
        server_name _;


        client_max_body_size    25m;


        if ($host = 'www.gazi.edu.tr' ) {
                rewrite  ^/(.*)$  http://gazi.edu.tr/$1  permanent;
        }

        location / {

                # First attempt to serve request as file, then
                # as directory, then fall back to index.html
                try_files $uri $uri/ /index.php?$args;

                #if (!-e $request_filename) {
                #       rewrite ^.*$ /index.php last;
                #}

        }

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

        location ~* \.(jpg|jpeg|gif|png|css|js|ico|xml)$ {
                access_log        off;
                log_not_found     off;
                expires           max;
                add_header Pragma public;
                add_header Cache-Control "public, must-revalidate, proxy-revalidate";

        }

                location ~ /\. {
                access_log off;
                log_not_found off;
                deny all;
        }


        location ~* ^/upload/.*.php$ {
                deny all;
                access_log off;
                log_not_found off;
        }

        location ~* ^/upload/.* {
                access_log off;
                log_not_found off;
                expires max;
                add_header Pragma public;
                add_header Cache-Control "public, must-revalidate, proxy-revalidate";
        }



        location /doc/ {
                alias /usr/share/doc;
                autoindex on;
                allow 127.0.0.1;
                deny all;
        }


        # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
        #
        location ~ \.php(.*)$ {
                try_files $uri =404;
                location ~ \..*/.*\.php$ {return 404;}

                fastcgi_split_path_info ^(.+\.php)(/.+)$;
                # NOTE: You should have "cgi.fix_pathinfo = 0;" in php.ini


                #fastcgi_pass 127.0.0.1:9000;
                #fastcgi_pass unix:/tmp/php5-fpm.sock;
                fastcgi_index index.php;

                #fastcgi_connect_timeout 60;
                #fastcgi_send_timeout 180;
                #fastcgi_read_timeout 180;
                #fastcgi_buffer_size 128k;
                #fastcgi_buffers 256 16k;
                #fastcgi_busy_buffers_size 256k;
                #fastcgi_temp_file_write_size 256k;
                fastcgi_intercept_errors on;
                #fastcgi_max_temp_file_size 0;

                fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
                fastcgi_param APPLICATION_ENV production;

                include fastcgi_params;

                #if ($request_uri ~* ^/admin) {
                #       return 301 http://gazi.edu.tr/admin
                #}


                fastcgi_pass admincluster;
                proxy_next_upstream error timeout invalid_header http_500 http_502 http_503;



        }

        # deny access to .htaccess files, if Apache's document root
        # concurs with nginx's one
        #
        #location ~ /\.ht {
        #       deny all;
        #}
}

I need to find out why the file without extension is downloading too slow, or even not downloading?

thanks in advance.