cookies are not send

Hello!

In my production environment there are no cookies sent to the client
when using the session hash...

Here is the login function:

  def check
    u = User.first(:conditions => ["nick = ?", params[:user]])

    if (u != nil) && (u.pass == params[:password])
      session[:user] = u.nick
      session[:lastlogin] = u.lastlogin
      u.lastlogin = Time.current
      u.save
      flash[:notice] = I18n.t("user.login.succesfull")
      redirect_to :controller => "user", :action => "dashboard"
    else
      reset_session
      flash[:error] = I18n.t("user.login.userOrPassWrong")
      redirect_to :controller => "user", :action => "login"
    end
  end

Yes I know it is not optimum but it fits my needs and is also on my
schedule to refactor :smiley:

In the development environment all works well as expected, in
production environment on localhost also, but when I deploy to my
engineyard for further testing, there are no more cookies sent to the
client.

I really dont know where to begin... Since it works with the same
config on the localhost but not on the yard (except the database
configs)