Wagn::Exceptions::Oops in CardController#create_or_update

error saving foo+*self+*read: error saving foo: error saving foo: Mysql::Error: Column 'created_at' cannot be null: INSERT INTO `cards` (`appender_id`, `appender_type`, `codename`, `created_at`, `created_by`, `current_revision_id`, `extension_id`, `extension_type`, `indexed_content`, `indexed_name`, `key`, `name`, `pattern_keys`, `read_rule_class`, `read_rule_id`, `reader_id`, `reader_type`, `references_expired`, `settings`, `tag_id`, `trash`, `trunk_id`, `typecode`, `updated_at`, `updated_by`) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?), /usr/cldstr/wagn.org/wagn/ws/gems/ruby/1.8/gems/activerecord-3.1.3/lib/active_record/connection_adapters/mysql_adapter.rb:890:in `execute'
/usr/cldstr/wagn.org/wagn/ws/gems/ruby/1.8/gems/activerecord-3.1.3/lib/active_record/connection_adapters/mysql_adapter.rb:890:in `exec_stmt'
/usr/cldstr/wagn.org/wagn/ws/gems/ruby/1.8/gems/activerecord-3.1.3/lib/active_record/connection_adapters/mysql_adapter.rb:434:in `exec_query'
/usr/cldstr/wagn.org/wagn/ws/gems/ruby/1.8/gems/activerecord-3.1.3/lib/active_record/connection_adapters/abstract_adapter.rb:244:in `log'
/usr/cldstr/wagn.org/wagn/ws/gems/ruby/1.8/gems/activesupport-3.1.3/lib/active_support/notifications/instrumenter.rb:21:in `instrument'
/usr/cldstr/wagn.org/wagn/ws/gems/ruby/1.8/gems/activerecord-