Resources created via OneToMany::Collection#new work, but not if conditions are applied

snippet.rb

require 'rubygems'
# puts ENV["GEM_HOME"]
require 'ruby-debug'
require 'datamapper'

DataMapper::Logger.new(STDOUT)
DataMapper.setup(:default, "sqlite::memory:")

class Page
  include DataMapper::Resource

  property :id,         Serial

  has n, :page_components,                                          :child_key => :page_id

  def masthead_left
    page_components(:section => "masthead_left")
  end
end

class PageComponent
  include DataMapper::Resource

  property :page_id,    Integer,      :key => true, :index => :page
  property :section,    String,       :key => true, :length => 32

  belongs_to :page, :child_key => :page_id, :inverse => :page_components

  def self.masthead_left
    all(:section => "masthead_left")
  end
end



DataMapper.auto_migrate!


puts '******* Explicit conditions to #new'

page = Page.create
component = page.page_components.new(:section => "masthead_right")
page.save
# components IS in page.components, page.save does cascade:

puts '******* Explicit conditions to association method'

page.reload
collection = page.page_components(:section => "masthead_left")
collection.class # => DataMapper::Associations::OneToMany::Collection
collection.query.conditions.class # => DataMapper::Query::Conditions::AndOperation
component = collection.new
page.save
# components is NOT in page.components, so save doesn't cascade

puts '******* Association-derived collection (#new via Collect#delegate_to_model)'

page.reload
component = page.page_components.masthead_left.new
page.save
# components is NOT in page.components, so save doesn't cascade

puts "*********************************"