Cannot create new issue for scenario

[jpolo]

When clicking on the board "new issue" the pane with spinner appears but nothing shows up...

In /var/log/redmine/default/production.log

Processing IssueSprintsController#new (for 193.50.7.162 at 2010-11-16 15:24:20) [GET]
Parameters: {"user_story_id"=>"85", "project_id"=>"besyde", "action"=>"new", "controller"=>"issue_sprints"}

NoMethodError (undefined method user_story_id=' for nil:NilClass): /vendor/plugins/redmine_sprints/app/controllers/issue_sprints_controller.rb:11:innew'
/vendor/rails/actionpack/lib/action_controller/base.rb:1256:in send' /vendor/rails/actionpack/lib/action_controller/base.rb:1256:inperform_action_without_filters'
/vendor/rails/actionpack/lib/action_controller/filters.rb:617:in call_filters' /vendor/rails/actionpack/lib/action_controller/filters.rb:610:inperform_action_without_benchmark'
/vendor/rails/actionpack/lib/action_controller/benchmarking.rb:68:in perform_action_without_rescue' /usr/lib/ruby/1.8/benchmark.rb:293:inmeasure'
/vendor/rails/actionpack/lib/action_controller/benchmarking.rb:68:in perform_action_without_rescue' /vendor/rails/actionpack/lib/action_controller/rescue.rb:136:inpassenger_orig_perform_action'
/usr/lib/ruby/1.8/phusion_passenger/railz/request_handler.rb:65:in perform_action' /vendor/rails/actionpack/lib/action_controller/base.rb:524:insend'
/vendor/rails/actionpack/lib/action_controller/base.rb:524:in process_without_filters' /vendor/rails/actionpack/lib/action_controller/filters.rb:606:inprocess_without_session_management_support'
/vendor/rails/actionpack/lib/action_controller/session_management.rb:134:in process_without_test' /vendor/rails/actionpack/lib/action_controller/test_process.rb:18:inprocess'
/vendor/rails/actionpack/lib/action_controller/base.rb:392:in process' /vendor/rails/actionpack/lib/action_controller/dispatcher.rb:184:inhandle_request'
/vendor/rails/actionpack/lib/action_controller/dispatcher.rb:112:in dispatch_unlocked' /vendor/rails/actionpack/lib/action_controller/dispatcher.rb:125:indispatch'

My script/about:

About your application's environment
Ruby version 1.8.7 (x86_64-linux)
RubyGems version 1.3.5
Rails version 2.2.3
Active Record version 2.2.3
Action Pack version 2.2.3
Active Resource version 2.2.3
Action Mailer version 2.2.3
Active Support version 2.2.3
Edge Rails revision unknown
Application root /usr/share/redmine
Environment production
Database adapter postgresql
Database schema version 20100221100219

About your Redmine plugins
Redmine Scrum Sprints plugin 0.1.6