As I study law, just for you to know: the directive 44/1999 of European Union provides there's a window of two years from delivery of a consumer product during which the consumer may claim that the product was defective.
That means also that if a product was purchased with an undetectable defect but that defect became apparent after a while, then the consumer would have a claim against the seller under EU Directive 1999/44 to repair the defect.
It "works" of course even if the defect in the product (which must be fit for their intended purposes) has not have been apparent at the time the consumer made the purchase.
If the consumer makes a claim within six months of delivery of the product that the product was defective at delivery, the burden is on the seller to prove that the product was not defective at the time of sale. From six to twenty-four months it is the consumerís obligation to prove that the defect in the product existed at the time the goods were delivered to the consumer.
Care on this because many wsurfers are lawyers and as lawyers with some spare time are used to do in troubled cases, it's just matter of time I think..