[Rails] 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: http://railscasts.com/episodes/196-nested-model-form-part-1?view=asciicast If I do it the same (only without nifty) the "new" Site of the CRUD methods doesnt show me the

[Rails] Nested model form problem, not saving, any help?

I have two models, Curso and Ementa class Curso < ActiveRecord::Base attr_accessible :nome, :descricao, :periodo_inscricao_inicio, > :periodo_inscricao_fim > has_one :ementa, :dependent => :destroy has_many :turmas has_many :publico_alvos > accepts_nested_attributes_for :ementa