Google's interface language

Previously I really enjoyed using google for websearching since I got the really relevant pages right on top of the result list. But since a few weeks (when I started using German as interface language) Google also started to prefer german links no matter what option I set in the google preferences for the result sets.

But first things first. The whole story started when I downloaded the german version of Mozilla Firefox since a mixed language interface sucks ;) Well, this comes with the german version of Google as default search engine which wouldn’t be really a problem if this would only result in a german interface and not also in prioritisizing of german hits.

Well, now I also switched the google interface to English and suddenly google works again :-? Perhaps someone should explain them, that the interface language shouldn’t have anything to do with the result set language.