"tags not loaded yet" : what does it mean

Hi all,

   >> pp.tags
   => <tags not loaded yet>

Is it a bug, or a feature that I don't understand yet?

I'm having a problem with some polymorphic through: associations.
I can reproduce the symptoms with the untouched Tag/Tagging from the
(official) acts_as_taggable plugin:

pp=Production.create(:genre_id => 540, :title_line_1 => "ee")
=> ...

pp.valid?

=> true

pp.tag_with 'one two'

=> ["one", "two"]

pp.tags

=> <tags not loaded yet> <<---------------------------- ???

Q/ what's happening here?

Alain Ravet