ProMotion MotionModel incompatibility

app_delegate.rb

class AppDelegate < PM::Delegate
  attr_reader :window

  def on_load(app, options)
    open ListEntriesScreen.new(nav_bar: true)
  end
end

entry.rb

class Entry

  include MotionModel::Model
  include MotionModel::ArrayModelAdapter

  columns :entry_date  => :date,
          :details    => :text,
          :created_at => :date,
          :updated_at => :date


  def after_save(sender)
    Entry.serialize_to_file('entries.dat')
  end
end

error

2013-06-25 22:51:44.769 BestFed[82629:c07] model.rb:802:in `method_missing:': undefined method `[]' for Entry#1:0x9ca8e40:Entry (NoMethodError)
  from _table.rb:106:in `tableView:titleForHeaderInSection:'
	from _table.rb:43:in `update_table_view_data:'
	from _table_screen_module.rb:9:in `update_table_data'
	from list_entries_screen.rb:17:in `block in on_load'
	from model.rb:320:in `issue_notification:'
	from model.rb:514:in `block in save_without_transaction:'
	from model.rb:541:in `call_hooks:'
	from model.rb:501:in `save_without_transaction:'
	from model.rb:494:in `save:'
	from model.rb:212:in `create:'
	from list_entries_screen.rb:51:in `new_entry'
2013-06-25 22:51:44.771 BestFed[82629:c07] *** Terminating app due to uncaught exception 'NoMethodError', reason: 'model.rb:802:in `method_missing:': undefined method `[]' for Entry#1:0x9ca8e40:Entry (NoMethodError)
	from _table.rb:106:in `tableView:titleForHeaderInSection:'
	from _table.rb:43:in `update_table_view_data:'
	from _table_screen_module.rb:9:in `update_table_data'
	from list_entries_screen.rb:17:in `block in on_load'
	from model.rb:320:in `issue_notification:'
	from model.rb:514:in `block in save_without_transaction:'
	from model.rb:541:in `call_hooks:'
	from model.rb:501:in `save_without_transaction:'
	from model.rb:494:in `save:'
	from model.rb:212:in `create:'
	from list_entries_screen.rb:51:in `new_entry'
'
*** First throw call stack:
(0x1e28012 0x977e7e 0x43cbdd 0x4042 0x30a5)
libc++abi.dylib: terminate called throwing an exception
*** simulator session ended with error: Error Domain=DTiPhoneSimulatorErrorDomain Code=1 "The simulated application quit." UserInfo=0x100113380 {NSLocalizedDescription=The simulated application quit., DTiPhoneSimulatorUnderlyingErrorCodeKey=-1}
rake aborted!
Command failed with status (1): [DYLD_FRAMEWORK_PATH="/Applications/Xcode.a...]
/Library/RubyMotion/lib/motion/project/template/ios.rb:112:in `block in <top (required)>'
Tasks: TOP => default => simulator
(See full trace by running task with --trace)

list_entries_screen.rb

class EntriesListScreen < ProMotion::TableScreen
  title "Entries"

  def on_load
    
    Entry.deserialize_from_file('entries.dat')
    @table_data = Entry.all

    @entry_model_change_observer = App.notification_center.observe MotionModelDataDidChangeNotification do |notification|
      if notification.object.is_a?(Entry)
        update_table_data
      end
    end

    #adds top right "new" button
    right_button = UIBarButtonItem.alloc.initWithBarButtonSystemItem(UIBarButtonSystemItemAdd, target:self, action:"new_entry")
    self.navigationItem.rightBarButtonItem = right_button
      
  end

  def will_appear
    @view_setup ||= set_up_view
  end

  def table_data
    @table_data = Entry.all
  end

  def new_entry
    #demo - just create new entry in tableview  
    Entry.create :details => "New entry"
  end

  def tapped_item(item)
    open EntryDetailScreen.new(item: item)
  end

  def set_up_view
    set_attributes self.view, {
      frame: [[0,0],[320,416]]
    }
  end

end