ZAML issue with classes.rb

# Code is from http://opensoul.org/2010/5/3/the-quest-for-the-holy-object-serialization-format

class Class
  yaml_as "tag:ruby.yaml.org,2002:class"

  def Class.yaml_new( klass, tag, val )
    if String === val
      val.split(/::/).inject(Object) {|m, n| m.const_get(n)}
    else
      raise YAML::TypeError, "Invalid Class: " + val.inspect
    end
  end

  def to_yaml( opts = {} )
    YAML::quick_emit( nil, opts ) { |out|
      out.scalar( "tag:ruby.yaml.org,2002:class", self.name, :plain )
    }
  end
end

# Under YAML

require "yaml"

yaml_created_file_class = YAML.load(YAML.dump(File)) # => File 
yaml_created_file_class.methods.grep(/exist/) # => ["exist?", "exists?"] 

# Under ZAML

require "zaml"

zaml_created_file_class = YAML.load(ZAML.dump(File)) # => #<Class:0x7f950e8fabd8> 
zaml_created_file_class.methods.grep(/exist/) # => [] 

RUBY_VERSION # => "1.8.7" 
defined?(RUBY_ENGINE) # => nil