Random RoutingError

Hi,
I'm getting "Page Cannot be Found" error. The funny (let's call it funny :) ) is that is random.
When I restart the server, I can log in into my web properly.
After a few minutes and server "log in's", it shows "Page Cannot be found"

I checked the production.log, and it complains about ActionController::RoutingError:

How can i debug this error? Why is it random?
Also, it surprise me, that the log says:
    "Processing Base#index" (instead of the name of the controller, AuthenticatorController)
    ActionController::RoutingError (Recognition failed for "/authenticator/auth/"):


thanks,

Jean

Here the logs:

Processing Base#index (for 1.2.3.4 at 2007-01-18 01:27:19) [GET]
  Session ID: 09f4870ca3e2b381646f00acee7c8c36
  Parameters: {"pwd"=>"a1ff1ead1ba7c17257687763772f2af69b753d16ce19b681fa0b232a2ec1bc43f79658b520e025fa2da137d768aa1b77bbf2a64529500e191dd7c2ac5dd44b5d6cad64e309132da29735562e1bcb626fae3c20448ae82c1121ba9afefed11fcf4c54b957a275596d221dd28d8f7d2608096f8cab7fd4f1089eb5283be0a5dd9b", "usr"=>"usert@testingcom"}


ActionController::RoutingError (Recognition failed for "/authenticator/auth/"):
    /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action_controller/routing.rb:522:in `recognition_failed'
    /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action_controller/routing.rb:512:in `recognize!'
    /usr/local/lib/ruby/gems/1.8/gems/rails-1.1.6/lib/dispatcher.rb:38:in `dispatch'
    /usr/local/lib/ruby/gems/1.8/gems/mongrel-0.3.13.3/lib/mongrel/rails.rb:73:in `process'
    /usr/local/lib/ruby/gems/1.8/gems/mongrel-0.3.13.3/lib/mongrel.rb:551:in `process_client'
    /usr/local/lib/ruby/gems/1.8/gems/mongrel-0.3.13.3/lib/mongrel.rb:550:in `process_client'
    /usr/local/lib/ruby/gems/1.8/gems/mongrel-0.3.13.3/lib/mongrel.rb:636:in `run'
    /usr/local/lib/ruby/gems/1.8/gems/mongrel-0.3.13.3/lib/mongrel.rb:636:in `run'
    /usr/local/lib/ruby/gems/1.8/gems/mongrel-0.3.13.3/lib/mongrel.rb:625:in `run'
    /usr/local/lib/ruby/gems/1.8/gems/mongrel-0.3.13.3/lib/mongrel.rb:956:in `run'
    /usr/local/lib/ruby/gems/1.8/gems/mongrel-0.3.13.3/lib/mongrel.rb:955:in `run'
    /usr/local/lib/ruby/gems/1.8/gems/mongrel-0.3.13.3/bin/mongrel_rails:127:in `run'
    /usr/local/lib/ruby/gems/1.8/gems/mongrel-0.3.13.3/lib/mongrel/command.rb:199:in `run'
    /usr/local/lib/ruby/gems/1.8/gems/mongrel-0.3.13.3/bin/mongrel_rails:235
    /usr/local/bin/mongrel_rails:18