Hi,¶

I get an "Internal error" when I click on "Create" on the "New issue" page or "Submit" on the "Update issue" page. On this error page I can click on "Back" and everything seems to be ok. The new/updated issue was stored. My installation runs on the webrick server and it gives the following outputs:
After clicking "Create"/"Submit" (which results in the error page):

Processing IssuesController#edit (for 192.168.66.175 at 2010-03-09 07:53:48) [POST]
  Parameters: {"time_entry"=>{"comments"=>"", "activity_id"=>"", "hours"=>""}, "commit"=>"OK", "notes"=>"", "action"=>"edit", "authenticity_token"=>"+lB+fcCwYCfIBY/IuIVlMzcbDlmVfWvoQzQrtDUyxpo=", "id"=>"873", "issue"=>{"start_date"=>"2010-03-08", "estimated_hours"=>"5", "priority_id"=>"4", "lock_version"=>"7", "done_ratio"=>"0", "assigned_to_id"=>"4", "subject"=>"Testfehler", "tracker_id"=>"1", "due_date"=>"2010-03-09", "status_id"=>"5", "description"=>"Mal sehen, was kaputt ist."}, "controller"=>"issues", "attachments"=>{"1"=>{"description"=>""}}}
Redirected to http://gateway:88/issues/873
Completed in 69ms (DB: 13) | 302 Found [http://gateway/issues/873/edit]

After clicking "Back" an the error page:

/!\ FAILSAFE /!\  Tue Mar 09 07:53:48 -0500 2010
  Status: 500 Internal Server Error
  undefined method `merge' for nil:NilClass
    /home/redmine-0.9.3/vendor/rails/actionpack/lib/action_controller/request.rb:385:in `parameters'
    /home/redmine-0.9.3/vendor/rails/actionpack/lib/action_controller/base.rb:1288:in `assign_shortcuts'
    /home/redmine-0.9.3/vendor/rails/actionpack/lib/action_controller/base.rb:527:in `process_without_filters'
    /home/redmine-0.9.3/vendor/rails/actionpack/lib/action_controller/filters.rb:606:in `process'
    /home/redmine-0.9.3/vendor/rails/actionpack/lib/action_controller/rescue.rb:65:in `call_with_exception'
    /home/redmine-0.9.3/vendor/rails/actionpack/lib/action_controller/dispatcher.rb:90:in `dispatch'
    /home/redmine-0.9.3/vendor/rails/actionpack/lib/action_controller/dispatcher.rb:121:in `_call'
    /home/redmine-0.9.3/vendor/rails/actionpack/lib/action_controller/dispatcher.rb:130
    /home/redmine-0.9.3/vendor/rails/activerecord/lib/active_record/query_cache.rb:29:in `call'
    /home/redmine-0.9.3/vendor/rails/activerecord/lib/active_record/query_cache.rb:29:in `call'
    /home/redmine-0.9.3/vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb:34:in `cache'
    /home/redmine-0.9.3/vendor/rails/activerecord/lib/active_record/query_cache.rb:9:in `cache'
    /home/redmine-0.9.3/vendor/rails/activerecord/lib/active_record/query_cache.rb:28:in `call'
    /home/redmine-0.9.3/vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb:361:in `call'
    /home/redmine-0.9.3/vendor/rails/actionpack/lib/action_controller/string_coercion.rb:25:in `call'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/head.rb:9:in `call'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/methodoverride.rb:24:in `call'
    /home/redmine-0.9.3/vendor/rails/actionpack/lib/action_controller/params_parser.rb:15:in `call'
    /home/redmine-0.9.3/vendor/rails/actionpack/lib/action_controller/session/cookie_store.rb:93:in `call'
    /home/redmine-0.9.3/vendor/rails/actionpack/lib/action_controller/failsafe.rb:26:in `call'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/lock.rb:11:in `call'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/lock.rb:11:in `synchronize'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/lock.rb:11:in `call'
    /home/redmine-0.9.3/vendor/rails/actionpack/lib/action_controller/dispatcher.rb:106:in `call'
    /home/redmine-0.9.3/vendor/rails/railties/lib/rails/rack/static.rb:31:in `call'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/urlmap.rb:46:in `call'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/urlmap.rb:40:in `each'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/urlmap.rb:40:in `call'
    /home/redmine-0.9.3/vendor/rails/railties/lib/rails/rack/log_tailer.rb:17:in `call'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/content_length.rb:13:in `call'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/handler/webrick.rb:50:in `service'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/1.8/webrick/httpserver.rb:104:in `service'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/1.8/webrick/httpserver.rb:65:in `run'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/1.8/webrick/server.rb:173:in `start_thread'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/1.8/webrick/server.rb:162:in `start'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/1.8/webrick/server.rb:162:in `start_thread'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/1.8/webrick/server.rb:95:in `start'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/1.8/webrick/server.rb:92:in `each'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/1.8/webrick/server.rb:92:in `start'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/1.8/webrick/server.rb:23:in `start'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/1.8/webrick/server.rb:82:in `start'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/handler/webrick.rb:14:in `run'
    /home/redmine-0.9.3/vendor/rails/railties/lib/commands/server.rb:111
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
    /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
    script/server:3

Processing IssuesController#show (for 192.168.66.175 at 2010-03-09 07:53:53) [GET]
  Parameters: {"action"=>"show", "id"=>"873", "controller"=>"issues"}
Rendering template within layouts/base
Rendering issues/show.rhtml
Completed in 138ms (View: 102, DB: 13) | 200 OK [http://gateway/issues/873]

My environment is:
About your application's environment
Ruby version 1.8.7 (i686-linux)
RubyGems version 1.3.5
Rack version 1.0
Rails version 2.3.5
Active Record version 2.3.5
Active Resource version 2.3.5
Action Mailer version 2.3.5
Active Support version 2.3.5
Edge Rails revision unknown
Application root /home/redmine-0.9.3
Environment production
Database adapter mysql
Database schema version 20100221100219

I installed ruby/rails/etc. via http://www.rubyenterpriseedition.com

Best regards!

P.S.: This happens on the demo.redmine.org site too!