Graticule / acts_as_geocodable error?

Has anyone encountered this error using Graticule &
acts_as_geocodable?

ActiveRecord::UnknownAttributeError (unknown attribute: precision):
(DELEGATION):2:in __send__' (__DELEGATION__):2:inwith_scope’
app/models/listing.rb:113:in `advanced_find’

Here is line 113 in listing.rb:

published.find(:all,
:origin => zip_code,
:within => miles,
:conditions => [conditions.join(" AND "), args, args],
:page => {:size => 10, :current => (page || ‘’)},
:order => ‘distance ASC’)

The only mention of ‘precision’ is in my schema:

t.decimal "latitude",    :precision => 15, :scale => 12
t.decimal "longitude",   :precision => 15, :scale => 12

and when I render the distance coming back:

Distance: <%= number_with_precision listing.distance,
:precision => 1 %> miles away

I can’t figure out what “attribute” it’s talking about. Thanks for
the help.