How can I configure Yast to switch languages completely?

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http://unix.stackexchange.com – I have an installation of openSUSE 11.4 which was installed in German. I started Yast2 (which displayed in German, like "Netzwerkdienste") and switched the language to English under "System" -> "Sprache". Yast2 downloaded some files, installed something and remained German ("Netzwerkdienste" can still be seen instead of, presumably, "Network Services"). I rebooted the machine, same result. I un-installed the German Yast language pack. Yast2 persists in displaying in German. I don't know how many of Yast2's screens are supposed to be translated, but I think it might only be the main screen (HowTos)