N20 leak?
Now I do personally always leave mine open and i have lost a bottle once in a blue moon.. but my reasoning is having nitrous on my vehicles.. that I will not chance not having the valve open, forgetting to open it when getting in my truck, car etc and getting in a situation where a. i think i have it open and find out the hard way that it wasn't, or knowing it's closed and that I forgot to open it.. and not racing someone i want to because of that
lol 

