Nested Model Form Problem

Hi,

I try to solve this problem for nearly 5 hours now. I want to create
Nested
Model Forms like in the Railscasts tutorial:

If I do it the same (only without nifty) the “new” Site of the CRUD
methods
doesnt show me the nested forms.

Can anyone tell me why it doesnt work? Does it have anything to do with
the
rails version? The tutorial ist from 2010…

My System:
Ruby version1.9.3 (i386-mingw32)RubyGems version2.0.7Rack
version1.5Rails
version4.0.0
I would be soooooooooooo glad to find an answere for this problem…