Issue with Nginx WPMultiSite

Hi,
I have a WP MultiSite and it works fine, except for a little issue…
In my server I have Debian Lenny (jeje yep, old-stable jaja), MySQL, PHP5 and of course Nginx (nginx works better than apache, I make some tests and the results were awesome).
Well… multisites works almost perfect as I said: when I upload an image into a post or page I can´t see it, for example the link to the image is:
http://www.midomain.net/news/files/2011/03/picture.png
http://www.midomain.net = MainSite
news = “secundary” site

But, when I introduce the URL on my browser (firefox, chromium, etc) I have this error:
No input file specified

After a big search in Google, I think that the problem is in my vhost config, which I’m leaving here:

server {
  listen 80;
  server_name www.ipichcb.rimed.cu;
  root /var/www/ipichcb;
  index index.php;

  location ~ \.php$ {
    fastcgi_pass 127.0.0.1:9000;
    include /etc/nginx/fastcgi_params;
    fastcgi_index index.php;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
  }
    rewrite  ^.*/files/(.*) /wp-content/blogs.php?file=$1;

if (!-e $request_filename) {
 rewrite  ^.+?(/wp-.*)     $1          last;
 rewrite  ^.+?(/.*\.php)$  $1          last;
 rewrite  ^               /index.php  last;
}
}

After trying to figure this out for myself (and obviously I couldn’t), I came here for help. Surely, the solution is simple, but I just can´t see it..
I want to specify that in my laptop (archlinux+httpd) all works perfect (but I don´t want to change nginx for apache in my servers). That´s the main reason for me to think that the problem is on my vhost’s configuration from my nginx server.

Thanks for all, I will appreciate the help that any user could give me.

Greetings.