I have lately up-to-date an internet site Sometimes onto Wordpress 3.. Something strange has began happening, where the www. has dissapeared in the Web addresses, and when you add the www. towards the URL (a large amount from the existing hardcoded links get it) it redirects you to definitely the house page URL.

Any ideas what is leading to this?

My .htaccess appears like the default for Wordpress 3. Multi-User

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

# uploaded files
RewriteRule ^([_0-9a-zA-Z-]+/)?files/(.+) wp-includes/ms-files.php?file=$2 [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]

The configurations during my wordpress-config.php associated with the multi-user are

/** Multi User */
define('WP_ALLOW_MULTISITE', true);

define( 'MULTISITE', true );
define( 'SUBDOMAIN_INSTALL', false );
$base = '/';
define( 'DOMAIN_CURRENT_SITE', 'xxxx.ca' );
define( 'PATH_CURRENT_SITE', '/' );
define( 'SITE_ID_CURRENT_SITE', 1 );
define( 'BLOG_ID_CURRENT_SITE', 1 );

The URL configurations for my domain is only the xxxx.ca, there is no www. infront from it.

What's inside your .htaccess? Anything such as this?:

RewriteEngine On 
RewriteCond %{HTTP_HOST} ^www.domain.com$ [NC]
RewriteRule ^(.*)$ http://domain.com/$1 [R=301,L]

That redirect block strips the www all Web addresses.

And do you know the site URL configurations in Dashboard/Configurations/General? Have they got the www? And have you got site Web addresses set up in wordpress-config.php?