Mongrel Crashes in Production

I have been getting this error on the production server after rails was updated to 2.0.2 and moreover this worked perfectly in the development mode. This crash occurs when no one is using the app for an hour or so. This is the error that I get in the logs. (nohup.out file). The production log doesnt show anything unusual. Please help me out guys.

   1. /usr/local/lib/ruby/gems/1.8/gems/mongrel-1.1.1/bin/../lib/mongrel/rails.rb:98:in    2. `reload!': undefined method `reset_application!' for    3. ActionController::Dispatcher:Class (NoMethodError)    4. from    5. /usr/local/lib/ruby/gems/1.8/gems/mongrel-1.1.1/bin/../lib/mongrel/rails.rb:95:in    6. `synchronize'    7. from    8. /usr/local/lib/ruby/gems/1.8/gems/mongrel-1.1.1/bin/../lib/mongrel/rails.rb:95:in    9. `reload!'   10. from   11. /usr/local/lib/ruby/gems/1.8/gems/mongrel-1.1.1/bin/../lib/mongrel/rails.rb:165:in   12. `reload!'   13. from   14. /usr/local/lib/ruby/gems/1.8/gems/mongrel-1.1.1/bin/../lib/mongrel/rails.rb:178:in   15. `setup_rails_signals'   16. from   17. /usr/local/lib/ruby/gems/1.8/gems/mongrel-1.1.1/bin/../lib/mongrel/configurator.rb:303:in   18. `call'   19. from   20. /usr/local/lib/ruby/gems/1.8/gems/mongrel-1.1.1/bin/../lib/mongrel/configurator.rb:303:in   21. `join'   22. from   23. /usr/local/lib/ruby/gems/1.8/gems/mongrel-1.1.1/bin/../lib/mongrel

Thanks in advance.