Unknown key(s): attributes, discard_if

HI,

Having just installed attribute_fu I'm getting the error
ArgumentError in DogsController#new
Unknown key(s): attributes, discard_if
I assume this is coming from my model has_many parameters
          :attributes => true,
          :discard_if => proc { |upload| upload.photo_file_size.nil?
I can only assume that I need an include or some path option somewhere
or I havent set up attribute_fu properly?