Ferret: wildcard field search dies

Using the current ferret gem (on Win-XP):

irb(main):001:0> require ‘ferret’
c:/ruby/lib/ruby/1.8/fileutils.rb:950: warning: already initialized
constant
OPT_TABLE
=> true

irb(main):002:0> include Ferret
=> Object

irb(main):003:0> index = Index::Index.new
=> #<Ferret::Index::Index:0x3477ba8 @qp=nil, …>

irb(main):004:0> index << “This is a new doc”
=> nil

irb(main):005:0> index.search_each(’*:this’) do |d, s| puts d end
NoMethodError: undefined method weight' for nil:NilClass from c:/ruby/lib/ruby/gems/1.8/gems/ferret-0.2.2/lib/ferret/search/index_searcher.rb:104:insearch’
from
c:/ruby/lib/ruby/gems/1.8/gems/ferret-0.2.2/lib/ferret/index/index.rb:588:in
do_search ' from c:/ruby/lib/ruby/gems/1.8/gems/ferret-0.2.2/lib/ferret/index/index.rb:291:insearch_ea
ch’
from
c:/ruby/lib/ruby/gems/1.8/gems/ferret-0.2.2/lib/ferret/index/index.rb:290:in
synchroni ze' from c:/ruby/lib/ruby/gems/1.8/gems/ferret-0.2.2/lib/ferret/index/index.rb:290:insearch_ea
ch’
from (irb):5
irb(main):006:0>