Hello,
I'm not sure if this is the case, since JoomSEF is off on the website, so I don't see a problem, but this is mostly caused by template using relative links to CSS instead of absolute ones.
As regards the RewriteBase - it isn't the folder your site is located on the server, it is a folder you use to access your site in web browser. For example:
Your site's URL is
www.kulturkommunikasjon.no/ - RewriteBase is /.
Some site's URL
www.something.com/maps/ - RewriteBase is /maps.
But in your case this didn't cause a problem, since you have the RewriteBase line commented out by '#'.
Best regards,
ARTIO Support Team