You could manually fix your german console problems by looking here:
http://www.knoppix.net/forum/viewtopic.php?t=310#1067

and/or ...

I would recommend installing the localepurge package. Selecting the locale(s) you wish to use when you set it up, after that whenever you install a package it will purge all unnecessary locale files from your system, then no unwanted locales can be used.

HTH

~rock