WordPress MU

We have conflicts with english and german on our wp-mu installation:

- in the admin menu the section "Site Wide Settings (These settings may be overridden by blog owners) Default Language" is set on german

- the wp-login and wp-admin menu is in german (Benutzername instead of Username, ...)

- the wp-signup is only in english in variouse forms (when i am logged in as admin it shows only english messages, as well when i want to registrate,...)

- the de_DE.mo and continents-cities-de_DE.mo are both installed at "wp-content/language" on the server

- i took a look into the de_DE.po file, which is the one including the same content as the de_DE.mo file but for making changes inside and there is nothing translated of the wp-signup texts.

My question is: Could this conflict be related to the de_DE.mo or is the wp-signup.php to be translated "by hand" without plugin?

Thanks for help

Did you just use a regualr WordPress (not mu) translation file?

hmm, yes!

i used the ones from this page:
http://wordpress-deutschland.org/download/sprachdatei/

and it is just written about wordpress, not about wordpress-mu.
i found some language-packs for wordpress-mu at: http://mu.bloggles.info/2008/02/14/installing-wordpressmu-in-your-language/
but not the german one. is there an official page where these packs are collected or is it still not existing in german?

ok, as someone else asked on twitter the same question it seems the german version is still not existing...

Well, I am looking for a full formal ("Sie") translated German file, too.