Redmine

Hello everybody,
I upgraded redmine 0.8.7 to version 0.9.3 on a windows xp server.
Main Redmine features still work (not issue filter or file upload, for instance), but in production.log I get a lot of routing errors like the following:

Processing ApplicationController#index (for 192.168.103.70 at 2010-04-02 09:56:04) [GET]
ActionController::RoutingError (No route matches "/javascripts/effects.js" with {:method=>:get}):
Rendering c:/prj_mgm/prog/redmine-0.8.4/public/404.html (404 Not Found)

• LOCAL GEMS
  actionmailer (2.3.5)
  actionpack (2.3.5)
  activerecord (2.3.5)
  activeresource (2.3.5)
  activesupport (2.3.5)
  cgi_multipart_eof_fix (2.5.0)
  fxri (0.3.7, 0.3.6)
  fxruby (1.6.16)
  gem_plugin (0.2.3)
  hpricot (0.8.2)
  log4r (1.1.7)
  mongrel (1.1.5)
  mongrel_cluster (1.0.5)
  mongrel_service (0.3.4)
  mysql (2.8.1)
  ptools (1.1.9)
  rack (1.1.0, 1.0.1)
  rails (2.3.5)
  rake (0.8.7, 0.8.3, 0.8.1)
  ruby-opengl (0.60.0)
  rubygems-update (1.3.6)
  test-unit (2.0.7)
  win32-api (1.4.6)
  win32-clipboard (0.5.2)
  win32-dir (0.3.6)
  win32-eventlog (0.5.2)
  win32-file (0.6.3)
  win32-file-stat (1.3.4, 1.3.1)
  win32-process (0.6.2)
  win32-sapi (0.1.5)
  win32-service (0.7.1)
  win32-sound (0.4.2)
  windows-api (0.4.0, 0.2.4)
  windows-pr (1.0.9, 0.9.3)

I've read a lot of similiar help messages and tried most of the proposed solutions, but none seems to solve my problem.
Can anyone help?

Thanks,
Enrico