Go see Damo at Airborne Kitesurfing in 2/10 Howe st Ossie Park - prompt turnaround time and hes good for a chin wag. Have a droool over some of the nice gear in there while your at it!
Kitefix has the best replacement valve system. They use the 3M adhesive and also add a tube of sealant for extra stick. Most good kite shops are stocking them now.
Yeah, come in to us at SOS Surf in freo and we'll fix it, usually while u wait. We also keep them on the shelf if you want to get one and do it yourself.