Problem after upgrading to ferret 0.10.0

uninitialized constant BooleanClause

RAILS_ROOT: /home/ghost/user/V_O_2/public/…/config/…

/usr/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active_support/dependencies.rb:123:in
const_missing' #{RAILS_ROOT}/vendor/plugins/acts_as_ferret/lib/acts_as_ferret.rb:173:inacts_as_ferret’
#{RAILS_ROOT}/app/models/vo_object.rb:8
#{RAILS_ROOT}/app/controllers/search_controller.rb:52:in `browse_view’

This error occured while loading the following files:
vo_object.rb
ferret/search/boolean_clause.rb

require ‘RMagick’
require ‘ferret’
include Ferret

class VoObject < ActiveRecord::Base

acts_as_ferret :fields=>
[‘short_description’,‘section’,‘sale_category’,‘sale_type’,‘outcode’,‘bedrooms’,
‘car_make’,‘new_or_used’,‘salary’,‘age’,‘price_range’,‘ferret_date_registered’,‘sponsored’]

 def VoObject.browse_results(section,sale_category,page,search_within)

bq = Ferret::Search::BooleanQuery.new
	search_input  = '*'


	if section
		if !section.empty?
			qp = Ferret::QueryParser.new("section")
		query = qp.parse("\"#{section}\"")
			bq.add_query(query, Ferret::Search::BooleanClause::Occur::MUST)
			filter_on =true
		end
	end

Caspar wrote:

uninitialized constant BooleanClause

0.10.0 is not compatible with 0.9.4, there are several differences that
make acts_as_ferret break.