Multi Language Mixing Problem

I have German and Turkish as extra languages.

When I load German language file for a clean system, I got %84 and works ok. But after that one when I add Turkish there are some problems.
First German %is 64 Turkish % is 62. German % has been decreased.

But the main problem is mix problem. German and Turkish ones mixes and some German words are in Turkish interface and vice versa!

I tried to first intall Turkish than German but that does not help also.

Any idea?