Sorry, but agree with craig on that one, most only offer a standard warranty, which in most cases means that you have to send them back to the seller for repair, which could take a while, unfortunately repair/service centres in this country are tightening up their restrictions for this imported lenses. Some HK shops offer international warranty on their lenses, but then again have heard problems with these as well unless UK reciept like Kerso off eBay, but have no experience of buying from HK.
Peter