Incearca sa pui in .htaccess urmatoarele randuri:

Cod:
RewriteEngine on 

RewriteCond %{HTTP_HOST} ^domeniu\.ro$ [NC]
RewriteRule ^(.*)$ http://www.domeniu.ro/$1 [R=301,L]

RewriteCond %{HTTP_HOST} ^domeniu\.org$ [NC]
RewriteRule ^(.*)$ http://www.domeniu.org/$1 [R=301,L]