Load this page with Mozilla via HTTPS and click on any of the links below. (They all link to this page, you will see which number you clicked on so you know this page really reloaded and does not come from a cache). When trying to load this page the fourth time via HTTPS Mozilla “refuses” to load any more pages (including this one) from https://www.informatik.uni-bremen.de/ :-( Every other https site still works, loading this page via http://, too. Mozilla must be restarted to “fix” it.
(tested with Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.6) Gecko/20050319 and the same version under Windows)