how do collections from associations access class methods?

Hi all-

I'm working on a little survey app. Basically, you can write and tag
questions (using acts_as_taggable_on_steroids) and it serves these
question to the user in random order.

I've defined a class method that returns a random question
(self.randomq in the Question model).

I've also set up a has_many :through association in the User model:
has_many :answered_questions, :through => :responses, :source
=> :question

Now, let's say I get an array of questions through the association,
like so:

u = User.find(:first)
u_questions = u.answered_questions => array of Question objects
q = u_questions.randomq => works! this collection can access the
Question class methods.

However, if I *don't* get my collection of questions through an
association, it barfs:

foo_questions = Question.find_tagged_with( "foo" ) => array of
Question objects
foo_questions.randomq => "no method" error. this collection can't
access the Question class methods.

Why is this? It it possible for me to hack the find_tagged_with
method to make this work?

Thanks a ton!

Altay

P.S. I'm guessing, but not sure, that it has something to do with
collection_reader_method (in line 561 of associations.rb, see below),
but I'm a little too n00b to decipher the magic:

555: def has_many(association_id, options = {}, &extension)
556: reflection = create_has_many_reflection(association_id,
options, &extension)
557:
558: configure_dependency_for_has_many(reflection)
559:
560: if options[:through]
561: collection_reader_method(reflection,
HasManyThroughAssociation)
562: else
563: add_multiple_associated_save_callbacks(reflection.name)
564: add_association_callbacks(reflection.name,
reflection.options)
565: collection_accessor_methods(reflection,
HasManyAssociation)
566: end
567:
568: add_deprecated_api_for_has_many(reflection.name)
569: end