A review board at the U.S. Patent and Trademark Office has invalidated a claim against Apple with help from rival Samsung. The two firms are normally on opposite ends of the rope when it comes to a tug of war over patents. The story began about a year ago, when a Texas court ordered Apple to pay $533 million to holding firm SmartFlash, after it argued Apple's iTunes infringes three of its patents. SmartFlash's claims related to technologies for payments, storage and copy protection. It's the payment patent that the review board has dismissed, stating that it covers a "fundamental economic practice long in existence in commerce."