RAILS3 new validation class not working

I am using the new validation class rails3 provides. The issue is it
keeps giving me an error in the whole app of:

:attributes cannot be blank

here is the class below. I commented out all of the code to do
anything but it still gives me the error. Ideas??

class FileUploadValidator < ActiveModel::EachValidator

  def validate_each(record, attribute, value)

  end

end