NameError in Import#index

undefined local variable or method `acts_as_versioned' for Model:Class

RAILS_ROOT: /usr/local/rails/public/../config/..
Application Trace | Framework Trace | Full Trace

/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:991:in `method_missing'
#{RAILS_ROOT}/app/models/model.rb:2

This error occured while loading the following files:
   model.rb

Request

Parameters: None

Show session dump

--- 
flash: !map:ActionController::Flash::FlashHash {}


Response
Headers: {"cookie"=>[], "Cache-Control"=>"no-cache"}

Date: 2006-03-09 09:52
Sender: Nobody

Is there any updates on this one?  I am having the same issues.