Got your numbers and ran them in the system. Our records show that the re-work has not been done on your machine. It's surprising the number of dealers that do the work and don't claim warranty on it. If you believe you had the valve replaced I believe it was. Our warranty dept have had a couple ( less than 6) of valves that have popped out a second time, but never a 3rd. Maybe the casting on these few didn't hold.
Regardless,a dealer will repair your vent at no charge. If you call ahead he most likely will do it as you wait.