This weekend Mike and I both had the problem of taking a horrible puff on our Solos because our watts somehow got bumped up to 40+ watts! Blech! I'd just put in a new coil and filled the tank so after correcting the watts I kept taking puffs and blowing it out. After about 1/4 tank the flavor settled down and now it's fine so the coil and juice was saved. Anyway, that's when we found that you can lock the Solo by holding down the up/down button for a few seconds until you see a tiny little lock on the screen. Hold it down again to unlock it so you can change the setting. You all probably already know this, but we had to learn the hard way.