strange redirect to register page

When new people come to my website when they type in http://WWW.domain.com they land on the homepage no problem

But just recently I noticed that when a new person types into their browser address bar domain.com Without the www they are automatically redirected to http://www.domain.com/register They did not land on the homepage.

I have a feeling it is related to the .htaccess file sine I updated it yesterday when I turned my site into multisite network status.

Here is the current .htaccess

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

# add a trailing slash to /wp-admin
RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ $2 [L]
RewriteRule . index.php [L]

Hope someone can help. let me know if other info is needed.