>> c = Chapter.create(:title => "How to version a model")
NoMethodError: undefined method `version=' for #<Chapter::Version:0x2187278>
	from /Library/Ruby/Gems/1.8/gems/activerecord-2.1.2/lib/active_record/attribute_methods.rb:251:in `method_missing'
	from /Users/jacob/bookblog/vendor/plugins/acts_as_versioned/lib/acts_as_versioned.rb:276:in `send'
	from /Users/jacob/bookblog/vendor/plugins/acts_as_versioned/lib/acts_as_versioned.rb:276:in `save_version'
	from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.2/lib/active_support/callbacks.rb:173:in `send'
	from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.2/lib/active_support/callbacks.rb:173:in `evaluate_method'
	from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.2/lib/active_support/callbacks.rb:161:in `call'
	from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.2/lib/active_support/callbacks.rb:93:in `run'
	from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.2/lib/active_support/callbacks.rb:92:in `each'
	from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.2/lib/active_support/callbacks.rb:92:in `send'
	from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.2/lib/active_support/callbacks.rb:92:in `run'
	from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.2/lib/active_support/callbacks.rb:272:in `run_callbacks'
	from /Library/Ruby/Gems/1.8/gems/activerecord-2.1.2/lib/active_record/callbacks.rb:298:in `callback'
	from /Library/Ruby/Gems/1.8/gems/activerecord-2.1.2/lib/active_record/callbacks.rb:208:in `create_or_update'
	from /Library/Ruby/Gems/1.8/gems/activerecord-2.1.2/lib/active_record/base.rb:2211:in `save_without_validation'
	from /Library/Ruby/Gems/1.8/gems/activerecord-2.1.2/lib/active_record/validations.rb:911:in `save_without_dirty'
	from /Library/Ruby/Gems/1.8/gems/activerecord-2.1.2/lib/active_record/dirty.rb:75:in `save_without_transactions'
	from /Library/Ruby/Gems/1.8/gems/activerecord-2.1.2/lib/active_record/transactions.rb:106:in `save'
	from /Library/Ruby/Gems/1.8/gems/activerecord-2.1.2/lib/active_record/connection_adapters/abstract/database_statements.rb:66:in `transaction'
	from /Library/Ruby/Gems/1.8/gems/activerecord-2.1.2/lib/active_record/transactions.rb:79:in `transaction'
	from /Library/Ruby/Gems/1.8/gems/activerecord-2.1.2/lib/active_record/transactions.rb:98:in `transaction'
	from /Library/Ruby/Gems/1.8/gems/activerecord-2.1.2/lib/active_record/transactions.rb:106:in `save'
	from /Library/Ruby/Gems/1.8/gems/activerecord-2.1.2/lib/active_record/transactions.rb:118:in `rollback_active_record_state!'
	from /Library/Ruby/Gems/1.8/gems/activerecord-2.1.2/lib/active_record/transactions.rb:106:in `save'
	from /Library/Ruby/Gems/1.8/gems/activerecord-2.1.2/lib/active_record/base.rb:644:in `create'
	from (irb):4>>