Each brand has their own way of doing things and also with each generation of cards. For ex. with Cayman, the pcb's were not serialized at all, just the coolers. Then with Tahiti they went back to serials on the pcb, nothing on cooler. On Hawaii it was serial on pcb, nothing on cooler however the customs and revised cards like teh wf did things differently. Take my Lightning, the pcb is not serialized but the backplate is, go figure. That said the only serial number that really counts is the pcb. Though in my experience if the box is serialized it should at least match the pcb. It's strange that yours does not. Did you buy it new?