Datamapper DataMapper

Anonymous associations don't seem to be working properly with the YAML adapter.

require 'rubygems'
require 'dm-core'
DataMapper.setup(:default, "yaml:db")

class Burger

    include DataMapper::Resource

    property :id, Serial
    property :name, String, :length => 1..65535
    has n, :toppings, :through => Resource, :model => "Condiment"
    has n, :extras, :through => Resource, :model => "Condiment"
    def to_s
            self.name
    end

end

class Condiment

    include DataMapper::Resource

    property :id, Serial
    property :name, String, :length => 1..65535
    def to_s
            self.name
    end

end

burger = Burger.create(:name => "Double Cheeseburger")

cheese = Condiment.create(:name => "Cheese")

burger.toppings << cheese
burger.extras << Condiment.create(:name => 'Bacon')
burger.save

puts "burger toppings: #{burger.toppings}"
puts "burger extras: #{burger.extras}"
burger.reload
puts "burger toppings: #{burger.toppings}"
puts "burger extras: #{burger.extras}"

josh@phenom:~/test$ ruby problem.rb
burger toppings: Cheese
burger extras: Bacon
burger toppings:
burger extras: