Remember to store with the valve button in, ans ideally barrel down.

This is a common fault, mine did/does it alot.

I thought rebuilding would help but didn't take accurate enough note of the sear screw settings and had to experiment, ad nauseum. It's worth it, they're a lovely thing once done.

There's a few good tutorials out there, but basically the best advice I csn give is take accurate notes and pics of all the screw adjustments as you go, the rest is fairly straight forward.

Good luck!