#1067 - invalid default value for created_at or updated_at in table sales_flat_order_item

Alter the columns:

SET sql_mode = 'ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION';
ALTER TABLE `sales_flat_order_item` CHANGE `created_at` `created_at` TIMESTAMP NULL DEFAULT NULL COMMENT 'Created At'; 
ALTER TABLE `sales_flat_order_item` CHANGE `updated_at` `updated_at` TIMESTAMP NULL DEFAULT NULL COMMENT 'Updated At';