You forgot the pinch of salt and a tablespoon of paprika...maybe some grated cheese...
Seriously though I've had the same problem, pretty frustrating...it's allways the seal at the housing crimp. I used to get a fuel additive that helped keep my early cars webbers from junking up and drying out when sitting, but found wd40 worked fine, also soaking parts in brake fluid will expand and soften certain types of seals, something like a auto trans "repair in a can" will do the same thing. Might try that on a dead one and see what happens...