Change User's Language OS X Server

Hello Apple Support Community,

I am currently working on my Personal Project for school and I have an issue in OS X Server.

I am trying to have users in the open directory that do not have English set as their user language. I want them to log on and have German as their interface and keyboard langauge.

The issue here is, the usual method of changing the language of the said user(s) in System Preferences will not work. If I change everything to Deutsch/German, it will return everything to English the next time I log on with the user account, which is necessary, as you need to log out a user in order to change his/her User Interface Language.

I have also changed the system languages of the client computers (sudo languagesetup) without any further success. 😟

This is really making me madder than it is supposed to.

If anybody is wondering, here is the setup I am using:

27' iMac, Fall 2011, Core i5, 8GB RAM, OS X ML Server 10.8.2

27' iMac, Summer 2013, Core i7, 8GB RAM, OS X ML 10.8.2

Power Mac G5, Late 2005, PPC G5 2.0 DC, 3GB RAM, MAC OS X LEP 10.5.8

Thank you for your help in advance! 🙂