Rails 2.2 sweeping error

It appears we are seeing an error when we enable
config.action_controller.perform_caching with our Rails 2.2 upgrade. My
initial hunch is this is related to acts_as_audited plugin but not sure.

has anyone encountered this error and have a fix ?

Rails 2.2.2, Jruby 1.1.6, Tomcat 5.5.27

undefined method controller_name' for nil:NilClass /usr/local/tomcat/webapps/myapp/WEB-INF/gems/gems/actionpack-2.2.2/lib/action_controller/caching/sweeping.rb:83:incallback’