The main blog of a Wordpress multisite stopped working

Here's a link to the problem at the Wordpress forum:

http://wordpress.org/support/topic/the- … ?replies=3">http://wordpress.org/support/topic/the-main-blog-is-not-accessible?replies=3

I'd just copy it here, but they have their own markup.

> I have a WordPress Multisite at characters.ssu.lt and I created a blog at heinrich-eisenhauer.characters.ssu.lt. The main blog displayed for the first day that I created it, and I was able to work with it, but now it's not accessible. The blog I made from it is still accessible. Both the home blog and the network area are inaccessible. I'm currently logged into the home blog still, and when I go to this URL http://characters.ssu.lt/wp-admin/network/ and insert www before it (http://www.characters.ssu.lt/wp-admin/network/) I'm able to get a very stripped down and very basic HTML version of the page. Here's a screenshot. Does anyone know what I need to fix this? Is the home blog supposed to be set to the www subdomain?