WordPress MU Domain Mapping Just Redirects to Main Site

I have done the following:

— Installer WordPress and enabled MU on the main site (main.com).

— Changed wp-config.php of the MU to the following:

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).*)  [L]
RewriteRule ^(.*.php)$  [L]
RewriteRule . index.php [L]

— Changed the second domain (second.com)’s nameservers to be the same as the main domain. Then I added the second domain as an addon domain in cPanel. For web root of the second domain I choosed htdocs/main.com (the directory where WP MU is installed).

I didn’t just park it, because the WordPress MU is not installed in the root directory of the cPanel account and I am using shared hosting.

— Installed the WP domain mapping plugin: http://wordpress.org/plugins/wordpress-mu-domain-mapping/

— Went to the Network admin in the main site and under Settings->Domain mapping, I’ve entered main.com in the “Server CNAME domain:” fields.

— Under Settings->Domains I’ve added the domain second.com as the main domain for the WP install with ID 2.

— Under Sites->All Sites I’ve edited site with ID 2 and changed its domain to be http://second.com, keeping the checkbox “Update siteurl and home as well.” checked.

Now when I visit second.com in my browser I simply get redirected to the main WP site – main.com, whereas it should show me the WordPress child site instead.