Thanks for the replay Brian,
it helped. A little bit.
With a simple vector shape it now looks good. But with the desired logo it still gets all messed up. I'm not sure if it's something in the complexity of the logo that C4D can't handle (would be strange though).
I'm attaching both the troubled C4D-render and the original vector. You can see that the left shape looks okay (also an imported EPS) but the logo get's all messed up in the front.

