Problem with Direct-Linking-Prevention

[Tamashii]

Hello!

Yesterday I've switched from Apache2 to Nginx - and ran into some 
problems with the rewrite Rules.

I tried to do something like:

SetEnvIf Referer mydomain\.com localreferer
<FilesMatch \.(rar|zip)$>
         Order deny,allow
         Deny from all
         Allow from env=localreferer
</FilesMatch>

(Which worked on Apache.)

And I came up with this:

         ## Stop Download Hijacking
         location ~* (\.rar|\.zip)$ {
                 if ($http_referer !~ 
^(http://www.mydomain.com|http://mydomain.com) ) {
                         return 444;
                 }
         }

Whole config for this server is:

server {
         root /home/mydomain/files;
         index index.php index.html;
         server_name download.mydomain.com;

         ## Stop Download Hijacking
         location ~* (\.rar|\.zip)$ {
                 if ($http_referer !~ 
^(http://www.mydomain.com|http://mydomain.com) ) {
                         return 444;
                 }
         }
         location / {
                 try_files $uri $uri/ /index.php;
         }

         include /etc/nginx/php;
}

Problem is - it seems to do nothing at all ... I can type a download 
link into my browser and it loads (should block that unless it was 
refered from mydomain).

Has anyone any ideas?

Thanks in advance!
Alexander