Hellp needed with sublist plugin

Is there somebody out there who has built a working thingy with the
Sublist plugin? I can’t get it to work. I get this error message:
undefined method `stringify_keys!’ for “2005”:String
RAILS_ROOT: ./script/…/config/…

Application Trace | Framework Trace | Full Trace
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/base.rb:1506:in
attributes=' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/base.rb:1354:ininitialize_without_callbacks’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/callbacks.rb:236:in
initialize' #{RAILS_ROOT}/vendor/plugins/sublist/sub_list/lib/sub_list_system.rb:44:ininitialize_days’
#{RAILS_ROOT}/vendor/plugins/sublist/sub_list/lib/sub_list_system.rb:41:in
initialize_days' #{RAILS_ROOT}/app/controllers/child_controller.rb:81:inupdate’
-e:3
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/base.rb:1506:in
attributes=' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/base.rb:1354:ininitialize_without_callbacks’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/callbacks.rb:236:in
initialize' #{RAILS_ROOT}/vendor/plugins/sublist/sub_list/lib/sub_list_system.rb:44:ininitialize_days’
#{RAILS_ROOT}/vendor/plugins/sublist/sub_list/lib/sub_list_system.rb:41:in
initialize_days' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.1/lib/action_controller/base.rb:910:inperform_action_without_filters’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.1/lib/action_controller/filters.rb:368:in
perform_action_without_benchmark' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.1/lib/action_controller/benchmarking.rb:69:inperform_action_without_rescue’
E:/Programmeren/Ruby/lib/ruby/1.8/benchmark.rb:293:in measure' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.1/lib/action_controller/benchmarking.rb:69:inperform_action_without_rescue’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.1/lib/action_controller/rescue.rb:82:in
perform_action' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.1/lib/action_controller/base.rb:381:inprocess_without_filters’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.1/lib/action_controller/filters.rb:377:in
process_without_session_management_support' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.1/lib/action_controller/session_management.rb:117:inprocess’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/rails-1.1.2/lib/dispatcher.rb:38:in
dispatch' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/rails-1.1.2/lib/webrick_server.rb:115:inhandle_dispatch’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/rails-1.1.2/lib/webrick_server.rb:81:in
service' E:/Programmeren/Ruby/lib/ruby/1.8/webrick/httpserver.rb:104:inservice’
E:/Programmeren/Ruby/lib/ruby/1.8/webrick/httpserver.rb:65:in run' E:/Programmeren/Ruby/lib/ruby/1.8/webrick/server.rb:173:instart_thread’
E:/Programmeren/Ruby/lib/ruby/1.8/webrick/server.rb:162:in
start_thread' E:/Programmeren/Ruby/lib/ruby/1.8/webrick/server.rb:95:instart’
E:/Programmeren/Ruby/lib/ruby/1.8/webrick/server.rb:92:in start' E:/Programmeren/Ruby/lib/ruby/1.8/webrick/server.rb:23:instart’
E:/Programmeren/Ruby/lib/ruby/1.8/webrick/server.rb:82:in start' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/rails-1.1.2/lib/webrick_server.rb:67:indispatch’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/rails-1.1.2/lib/commands/servers/webrick.rb:59
E:/Programmeren/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:21:in
require' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active_support/dependencies.rb:147:inrequire’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/rails-1.1.2/lib/commands/server.rb:30
E:/Programmeren/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:21:in
require' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active_support/dependencies.rb:147:inrequire’
script/server:3
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/base.rb:1506:in
attributes=' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/base.rb:1354:ininitialize_without_callbacks’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/callbacks.rb:236:in
initialize' #{RAILS_ROOT}/vendor/plugins/sublist/sub_list/lib/sub_list_system.rb:44:ininitialize_days’
#{RAILS_ROOT}/vendor/plugins/sublist/sub_list/lib/sub_list_system.rb:41:in
initialize_days' #{RAILS_ROOT}/app/controllers/child_controller.rb:81:inupdate’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.1/lib/action_controller/base.rb:910:in
perform_action_without_filters' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.1/lib/action_controller/filters.rb:368:inperform_action_without_benchmark’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.1/lib/action_controller/benchmarking.rb:69:in
perform_action_without_rescue' E:/Programmeren/Ruby/lib/ruby/1.8/benchmark.rb:293:inmeasure’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.1/lib/action_controller/benchmarking.rb:69:in
perform_action_without_rescue' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.1/lib/action_controller/rescue.rb:82:inperform_action’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.1/lib/action_controller/base.rb:381:in
process_without_filters' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.1/lib/action_controller/filters.rb:377:inprocess_without_session_management_support’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.1/lib/action_controller/session_management.rb:117:in
process' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/rails-1.1.2/lib/dispatcher.rb:38:indispatch’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/rails-1.1.2/lib/webrick_server.rb:115:in
handle_dispatch' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/rails-1.1.2/lib/webrick_server.rb:81:inservice’
E:/Programmeren/Ruby/lib/ruby/1.8/webrick/httpserver.rb:104:in service' E:/Programmeren/Ruby/lib/ruby/1.8/webrick/httpserver.rb:65:inrun’
E:/Programmeren/Ruby/lib/ruby/1.8/webrick/server.rb:173:in
start_thread' E:/Programmeren/Ruby/lib/ruby/1.8/webrick/server.rb:162:instart_thread’
E:/Programmeren/Ruby/lib/ruby/1.8/webrick/server.rb:95:in start' E:/Programmeren/Ruby/lib/ruby/1.8/webrick/server.rb:92:instart’
E:/Programmeren/Ruby/lib/ruby/1.8/webrick/server.rb:23:in start' E:/Programmeren/Ruby/lib/ruby/1.8/webrick/server.rb:82:instart’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/rails-1.1.2/lib/webrick_server.rb:67:in
dispatch' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/rails-1.1.2/lib/commands/servers/webrick.rb:59 E:/Programmeren/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:21:inrequire’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active_support/dependencies.rb:147:in
require' E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/rails-1.1.2/lib/commands/server.rb:30 E:/Programmeren/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:21:inrequire’
E:/Programmeren/Ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active_support/dependencies.rb:147:in
`require’
script/server:3
-e:3
Request
Parameters: {“commit”=>“Edit”, “id”=>“1”,
“child”=>{“startdate(1i)”=>“2005”, “startdate(2i)”=>“9”,
“startdate(3i)”=>“1”, “group_id”=>“1”, “firstname”=>“Victor”,
“characteristics”=>"", “enddate(1i)”=>“2006”, “enddate(2i)”=>“7”,
“enddate(3i)”=>“1”, “parent”=>#<Parent:0x37fbad0
@attributes={“prefix”=>“van”, “enddate”=>“2006-07-01”,
“postcode”=>“1234AB”, “adress”=>“Astraat”, “doctor_id”=>“1”,
“lastname”=>“Vleuten”, “id”=>“1”, “phone”=>“0123456789”,
“town”=>“Groningen”, “startdate”=>“2005-09-01”}>},
“day”=>{“startdate(1i)”=>“2005”, “startdate(2i)”=>“9”,
“startdate(3i)”=>“1”, “2”=>{“tuesday”=>“1”, “thursday”=>“1”,
“monday”=>“1”, “friday”=>“0”}, “enddate(1i)”=>“2005”,
“enddate(2i)”=>“12”, “4”=>{“tuesday”=>“0”, “thursday”=>“0”,
“monday”=>“1”, “friday”=>“0”}, “enddate(3i)”=>“31”},
“parent”=>{“lastname”=>“Vleuten”}}

The view seems to be working, but when I try to save my changes it won’t
do so. Any pointers?