read the topic, still everything correct

In the Main catalogue I have
kummik.jpg
kummik_01.jpg
kummik_02.jpg

I got a bit deeper by searcing the answer now
in my window Admin->Catalog->Product Types->Product General->Edit Layout->Show Additional Images = true
(should be selection 0 or 1 , I have selection true,false???) - maybe thats messing something up?