Redmine

Hello.
I've upgraded Redmine from 1.4 to 2.1 and it was fine but when i open issues containg attachments with russian letters - i have 404 error.
Like this:

Started GET "/attachments/download/1078/всплывающее окно.pptx" for *.*.*.* at Wed Oct 24 18:54:00 +0400 2012
Processing by AttachmentsController#download as HTML
  Parameters: {"id"=>"1078", "filename"=>"всплывающее окно.pptx"}
  Current user: user (id=9)
  Rendered common/error.html.erb within layouts/base (0.2ms)
  Rendered plugins/redmine_improved_searchbox/app/views/redmine_improved_searchbox/_redmine_improved_searchbox_partial.html.erb (0.1ms)
Filter chain halted as :file_readable rendered or redirected
Completed 404 Not Found in 51ms (Views: 39.4ms | ActiveRecord: 2.1ms)

Attachments named in english are ok. what can be wrong????
My env

Environment:
  Redmine version                          2.1.2.stable
  Ruby version                             1.8.7 (i486-linux)
  Rails version                            3.2.8
  Environment                              production
  Database adapter                         MySQL
Redmine plugins:
  notify_custom_users                      0.0.4
  redmine_anonymous_watchers               0.0.1
  redmine_custom_workflows                 0.0.3
  redmine_equipment_status_viewer          1.0.0
  redmine_improved_searchbox               0.0.2
  redmine_inline_attach_screenshot         0.4.2
  redmine_knowledgebase                    2.1.2
  redmine_logs                             0.0.5
  redmine_monitoring_controlling           0.1.1
  redmine_textilizable_custom_fields       0.0.1
  redmine_wiki_toc                         0.0.4