I've did it..sjeeez...

No more errors/warnings and I can enter my admin online now!

I didn't saw that I had to download and run the fix_cache_key.php from here http://www.zen-cart.com/index.php?ma...products_id=82. After running the script it was a peace of cake. The script did all the work

Sometimes you look to deep, that you don't see the surface anymore

Well, maybe it also help others.
good luck!