has_many through combinations error

I have these classes:

class FilmTitle < ActiveRecord::Base
  has_many :films_film_titles
  has_many :films, :through => :films_film_titles
  has_many :assets, :through => :films
end

class Film < ActiveRecord::Base
  has_many :assets
end

class FilmsFilmTitle < ActiveRecord::Base
  belongs_to :film
  belongs_to :film_title
end

class Asset < ActiveRecord::Base
  belongs_to :film
end

but this does not work:

ft = FilmTitle.find 13
ft.assets <- throws error:
ActiveRecord::StatementInvalid: Mysql::Error: Unknown column
'films.film_title_id' in 'where clause': SELECT `assets`.* FROM
`assets` INNER JOIN films ON assets.film_id = films.id WHERE
((`films`.film_title_id = 13))

How can I get to these?

I have these classes:

class FilmTitle < ActiveRecord::Base
has_many :films_film_titles
has_many :films, :through => :films_film_titles
has_many :assets, :through => :films
end

Last I heard, nested has many throughs like this weren't supported.

Fred

Well that's a drag.
The SQL is easy... but I was hoping to make a named_scope.