The error is coming from the :include because your association doesn't define the table name. I believe you want your association to look like
class User has_many :notes, :order => "notes.created_at desc" end
As far as I know you can't prevent that from scoping all your find calls; However, in your case the order is the same in the association as the find, so, who cares.
Side note, this is harder to read but an alternative solution that will stay locked to your note table name if you change it or something later.
class User has_many :notes, :order => "#{Note.table_name}.created_at desc" end
