im having a problem with my site as i tried to go live. i have at least 15 sites hosted on the same server, and im trying to make a silverstripe site in the main directory, what i did was put it in a subfolder and use the mod rewrite to get everything in order. Everything is working now except the canonicalization i guess. When i go to the site using http://sitename.com it works and when i use http://www.sitename.com gives me. The website server has not been able to respond to your request. Here is what i have in the .htaccess
<IfModule mod_rewrite.c>
RewriteEngine on

RewriteCond %{HTTP_HOST} ^(www.)?sitename.com$

RewriteCond %{REQUEST_URI} !^/mainsitefolder/
#RewriteCond %{REQUEST_URI} !(\.gif)|(\.jpg)|(\.png)|(\.css)|(\.js)|(.php)$

RewriteCond %{REQUEST_URI} ^(.*)$
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{HTTP_HOST} ^(www.)?sitename.com$
RewriteRule .* mainsitefolder/sapphire/main.php?url=%1&%{QUERY_STRING}

</IfModule>
### SILVERSTRIPE END ###

any help would be much appreciated