Rails 3.2.9 different outputs from different domains - ruby

Question

So I decided to write my first Rails application.
Set up locally, added Mongoid to make it rich with data, added route to documents#index, launched rails -s in development mode - on localhost everything works fine, i see a beautiful list of documents available at my demand.
BUT!
My IP is visible from outside world, so I attached it to a domain from no-ip.org. Opened the same page and saw this terrifying stacktrace:
Started GET "/documents" for ..*.* at 2012-12-15 17:58:09 +0400
NoMethodError (undefined method `key?' for nil:NilClass):
actionpack (3.2.9) lib/action_controller/metal/hide_actions.rb:36:in `visible_action?'
actionpack (3.2.9) lib/action_controller/metal/hide_actions.rb:18:in `method_for_action'
actionpack (3.2.9) lib/action_controller/metal/implicit_render.rb:14:in `method_for_action'
actionpack (3.2.9) lib/action_controller/metal/compatibility.rb:61:in `method_for_action'
actionpack (3.2.9) lib/abstract_controller/base.rb:115:in `process'
actionpack (3.2.9) lib/abstract_controller/rendering.rb:45:in `process'
actionpack (3.2.9) lib/action_controller/metal.rb:203:in `dispatch'
actionpack (3.2.9) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch'
actionpack (3.2.9) lib/action_controller/metal.rb:246:in `block in action'
actionpack (3.2.9) lib/action_dispatch/routing/route_set.rb:73:in `call'
actionpack (3.2.9) lib/action_dispatch/routing/route_set.rb:73:in `dispatch'
actionpack (3.2.9) lib/action_dispatch/routing/route_set.rb:36:in `call'
journey (1.0.4) lib/journey/router.rb:68:in `block in call'
journey (1.0.4) lib/journey/router.rb:56:in `each'
journey (1.0.4) lib/journey/router.rb:56:in `call'
actionpack (3.2.9) lib/action_dispatch/routing/route_set.rb:601:in `call'
actionpack (3.2.9) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call'
rack (1.4.1) lib/rack/etag.rb:23:in `call'
rack (1.4.1) lib/rack/conditionalget.rb:25:in `call'
actionpack (3.2.9) lib/action_dispatch/middleware/head.rb:14:in `call'
actionpack (3.2.9) lib/action_dispatch/middleware/params_parser.rb:21:in `call'
actionpack (3.2.9) lib/action_dispatch/middleware/flash.rb:242:in `call'
rack (1.4.1) lib/rack/session/abstract/id.rb:205:in `context'
rack (1.4.1) lib/rack/session/abstract/id.rb:200:in `call'
actionpack (3.2.9) lib/action_dispatch/middleware/cookies.rb:341:in `call'
activerecord (3.2.9) lib/active_record/query_cache.rb:64:in `call'
activerecord (3.2.9) lib/active_record/connection_adapters/abstract/connection_pool.rb:479:in `call'
actionpack (3.2.9) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
activesupport (3.2.9) lib/active_support/callbacks.rb:405:in `_run__413099900__call__336258148__callbacks'
activesupport (3.2.9) lib/active_support/callbacks.rb:405:in `__run_callback'
activesupport (3.2.9) lib/active_support/callbacks.rb:385:in `_run_call_callbacks'
activesupport (3.2.9) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (3.2.9) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (3.2.9) lib/action_dispatch/middleware/reloader.rb:65:in `call'
actionpack (3.2.9) lib/action_dispatch/middleware/remote_ip.rb:31:in `call'
actionpack (3.2.9) lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call'
actionpack (3.2.9) lib/action_dispatch/middleware/show_exceptions.rb:56:in `call'
railties (3.2.9) lib/rails/rack/logger.rb:32:in `call_app'
railties (3.2.9) lib/rails/rack/logger.rb:16:in `block in call'
activesupport (3.2.9) lib/active_support/tagged_logging.rb:22:in `tagged'
railties (3.2.9) lib/rails/rack/logger.rb:16:in `call'
actionpack (3.2.9) lib/action_dispatch/middleware/request_id.rb:22:in `call'
rack (1.4.1) lib/rack/methodoverride.rb:21:in `call'
rack (1.4.1) lib/rack/runtime.rb:17:in `call'
activesupport (3.2.9) lib/active_support/cache/strategy/local_cache.rb:72:in `call'
rack (1.4.1) lib/rack/lock.rb:15:in `call'
actionpack (3.2.9) lib/action_dispatch/middleware/static.rb:62:in `call'
railties (3.2.9) lib/rails/engine.rb:479:in `call'
railties (3.2.9) lib/rails/application.rb:223:in `call'
rack (1.4.1) lib/rack/content_length.rb:14:in `call'
railties (3.2.9) lib/rails/rack/log_tailer.rb:17:in `call'
rack (1.4.1) lib/rack/handler/webrick.rb:59:in `service'
C:/Ruby193/lib/ruby/1.9.1/webrick/httpserver.rb:138:in `service'
C:/Ruby193/lib/ruby/1.9.1/webrick/httpserver.rb:94:in `run'
C:/Ruby193/lib/ruby/1.9.1/webrick/server.rb:191:in `block in start_thread'
Rendered C:/Ruby193/lib/ruby/gems/1.9.1/gems/actionpack-3.2.9/lib/action_dispatch/middleware/templates/rescues/_trace.erb (1.0ms)
Rendered C:/Ruby193/lib/ruby/gems/1.9.1/gems/actionpack-3.2.9/lib/action_dispatch/middleware/templates/rescues/_request_and_response.erb (1.0ms)
Rendered C:/Ruby193/lib/ruby/gems/1.9.1/gems/actionpack-3.2.9/lib/action_dispatch/middleware/templates/rescues/diagnostics.erb within rescues/layout (23.0ms)
This is the line that rails refuses to interpret:
return #visible_actions[action_name] if #visible_actions.key?(action_name)
The more - the better, when I launched my server in Production mode, both localhost and custom domain spat the same stack trace in my face.
What is wrong?
UPDATE
My routes.rb file:
DiplomaRails::Application.routes.draw do
resources :documents
resources :doc_sets
end
My Gemfile:
source 'https://rubygems.org'
gem 'rails', '3.2.9'
# Bundle edge Rails instead:
# gem 'rails', :git => 'git://github.com/rails/rails.git'
# Gems used only for assets and not required
# in production environments by default.
group :assets do
gem 'sass-rails', '~> 3.2.3'
gem 'coffee-rails', '~> 3.2.1'
# See https://github.com/sstephenson/execjs#readme for more supported runtimes
# gem 'therubyracer', :platforms => :ruby
gem 'uglifier', '>= 1.0.3'
end
gem 'jquery-rails'
gem "mongoid", "~> 3.0.0"