After each shot, attempts to fill it with gas result in more green gas in the environment and a very unpleasant noise. I was able to fix this by taking apart the grenade and manually resetting (removing and reinserting) the activation valve. I actually have to unscrew the top, remove the activation valve completely, and reset it, this sometimes includes a "chasing after the bearings" phase as they're only held in by lithium grease. Don't try this in the field or you'll be crying over spilt bearings. I find this irritating but it works every time, and I have to do it every time. Maybe this will change when the weather warms up.
For some reason, however, I don't mind doing this too much. I suppose because I really like the way it looks and like the whole lug locking thing. I guess I'm just a lug lockin' fool. Don't lock lugs with me son!
You can reset the grenade by pushing the trigger plate all the way in by using a long enough rod. There is instrustion that tells you how to reset it with out taking it apart. Push it all the way in until you hear a click.