Problem using filecolumn for file upload

I have uploaded filecloumn plugin using instructions from:

http://www.kanthak.net/opensource/file_column/index.html#download

And in my model I am giving :

class Company < ActiveRecord::Base
file_column :logo_filepathname
end

But when trying to display a form I am getting this error :

undefined method `file_column’ for Company:Class
RAILS_ROOT: ./script/…/config/…

Application Trace | Framework Trace | Full Trace
C:/instantrails/InstantRails/ruby/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/base.rb:1235:in
method_missing' #{RAILS_ROOT}/app/models/company.rb:2 #{RAILS_ROOT}/app/controllers/home_controller.rb:93:in login’

Am I missing some step? I don’t have file_column folder under the
plugins in vendor. Folder structure that I got after install is :

appfolder
|
|–vendor
|
|
–plugins
|
|
–trunk
|
|
–lib
|
|
file_column.rb

Thanks for any help.