redirect loop only on new sites, not previously set up sites.

I’ve been running multisite for over a year now, with a main site and one sub site, with sub-directories. Domain mapping and everything has worked perfectly with the second site.

I tried to create two more sites this week. When I try to access them, I get the redirect loop, right out of the box (dashboard works, I can create posts etc, but when I want to view the site – redirect loop). I have always set all URLs without the http://www., and searching the database entires didn’t yield any “www.” either.

I tried tweaking the .htaccess (but never changed it since setting up multisite and the second site that works). I’ve disabled all plugins and the issue persists. What baffles me the most is that the old sub site works, but the new ones don’t. Any ideas?