Redmine

We have Redmine 1.4.0.stable (MySQL) running on the Apache.
It had been possible to add a new category or version directly from the New Issue page until (I believe) I disabled the Support tracker for the current project. After that, neither category nor version can't be added (the dialog just dismisses), and the log contains the following messages.
Maybe it's not the Support tracker, however, since enabling it back or turning off completely doesn't help.

Processing IssuesController#new (for 192.168.147.102 at 2012-04-27 17:06:48) [GET]
Parameters: {"action"=>"new", "project_id"=>"cfc", "controller"=>"issues"}
Rendering template within layouts/base
Rendering issues/new
Completed in 414ms (View: 299, DB: 90) | 200 OK [http://--address--/projects/cfc/issues/new]

Processing ApplicationController#index (for 192.168.147.102 at 2012-04-27 17:07:00) [POST]
Parameters: {"category"=>{"name"=>"test"}}

ActionController::MethodNotAllowed (Only get requests are allowed.):
passenger (3.0.12) lib/phusion_passenger/rack/request_handler.rb:96:in `process_request'
passenger (3.0.12) lib/phusion_passenger/abstract_request_handler.rb:513:in `accept_and_process_next_request'
passenger (3.0.12) lib/phusion_passenger/abstract_request_handler.rb:274:in `main_loop'
passenger (3.0.12) lib/phusion_passenger/classic_rails/application_spawner.rb:321:in `start_request_handler'
passenger (3.0.12) lib/phusion_passenger/classic_rails/application_spawner.rb:275:in `send'
passenger (3.0.12) lib/phusion_passenger/classic_rails/application_spawner.rb:275:in `handle_spawn_application'
passenger (3.0.12) lib/phusion_passenger/utils.rb:479:in `safe_fork'
passenger (3.0.12) lib/phusion_passenger/classic_rails/application_spawner.rb:270:in `handle_spawn_application'
passenger (3.0.12) lib/phusion_passenger/abstract_server.rb:357:in `__send__'
passenger (3.0.12) lib/phusion_passenger/abstract_server.rb:357:in `server_main_loop'
passenger (3.0.12) lib/phusion_passenger/abstract_server.rb:206:in `start_synchronously'
passenger (3.0.12) lib/phusion_passenger/abstract_server.rb:180:in `start'
passenger (3.0.12) lib/phusion_passenger/classic_rails/application_spawner.rb:149:in `start'
passenger (3.0.12) lib/phusion_passenger/spawn_manager.rb:219:in `spawn_rails_application'
passenger (3.0.12) lib/phusion_passenger/abstract_server_collection.rb:132:in `lookup_or_add'
passenger (3.0.12) lib/phusion_passenger/spawn_manager.rb:214:in `spawn_rails_application'
passenger (3.0.12) lib/phusion_passenger/abstract_server_collection.rb:82:in `synchronize'
passenger (3.0.12) lib/phusion_passenger/abstract_server_collection.rb:79:in `synchronize'
passenger (3.0.12) lib/phusion_passenger/spawn_manager.rb:213:in `spawn_rails_application'
passenger (3.0.12) lib/phusion_passenger/spawn_manager.rb:132:in `spawn_application'
passenger (3.0.12) lib/phusion_passenger/spawn_manager.rb:275:in `handle_spawn_application'
passenger (3.0.12) lib/phusion_passenger/abstract_server.rb:357:in `__send__'
passenger (3.0.12) lib/phusion_passenger/abstract_server.rb:357:in `server_main_loop'
passenger (3.0.12) lib/phusion_passenger/abstract_server.rb:206:in `start_synchronously'
passenger (3.0.12) helper-scripts/passenger-spawn-server:99