Cookiless Domain

I’ve been trying for that past 10 hours to try to get cookiless domain to work with multisite. I’ve got it working on single site if I convert the WP installation to a single site but when I switch it to MS it doesn’t take.

Here’s the code in my wp-config file:

...
define('WP_ALLOW_MULTISITE', true);
define('MULTISITE', true);
#define('SUBDOMAIN_INSTALL', false);
define('DOMAIN_CURRENT_SITE', 'xxxxxx');
define('PATH_CURRENT_SITE', '/');
define('SITE_ID_CURRENT_SITE', 1);
define('BLOG_ID_CURRENT_SITE', 1);
define('SUNRISE', 'on');
...
define("WP_CONTENT_URL", "http://static.xxxxx.com");
define("COOKIE_DOMAIN", "www.xxxxx.com");
define("WP_PLUGIN_URL", "http://www.xxxxxx.com/wp-content/plugins");

and in my htaccess file:

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]

## add a trailing slash to /wp-admin
RewriteRule ^wp-admin$ wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule ^(wp-(content|admin|includes).*) $1 [L]
RewriteRule ^(.*\.php)$ $1 [L]
RewriteRule . index.php [L]

Cans someone please advise me. Thanks