I purchased one of these lighters a few days ago and, exceptionally for me, read the instructions before using it. They informed me how to adjust the flame height with a screwdriver and also mentioned that it was important not to turn the adjuster beyond the point where resistance was felt, lest I damaged the lighter. Well, I felt no resistance; nevertheless I seem to have damaged the lighter because it started leaking gas from its rear end, and I can now have either gas leaking away, or the gas not lighting, i.e. when I turn the adjuster enough to stop the leak, the lighter doesn't light. Even when I can't hear the leak, the gas leaks out in a matter of hours. I've dismantled and re-assembled the device, doubtless invalidating the warranty in the process, but couldn't see a problem to fix. OK, I know I must have damaged the lighter when I tried to adjust the flame, but it's a pretty awful design that allows it to be damaged to easily!