When was callback registration introduced?

I'm using Rails 2.3.5 and finding that for lines like these below in a model,
the block is never executed. Am I doing something wrong or was this
introduced in a later version of Rails?

  before_create :preprocess_score

  def preprocess_score
    puts "HERE: #{__LINE__}"
    self['score'] = Token.process(token_counts, feed.user_id)


  before_create do |a|
    puts "HERE"
    a.write_attribute('score', Token.process(token_counts, a.feed.user_id))


Never mind, bitten by fixtures. They aren't created normally and the
callbacks aren't called.


Quoting Jeffrey L. Taylor <ror@abluz.dyndns.org>: