Have same issues with leaking through the bottom. It's not the fill screw, because vacume was so strong, I couldn't unscrew until I removed the top part. I always keep my airflow all the way open and fill to half or so. So, it's either not enough wick ( I use 2mm inner diameter ), flawed Lemo ( could be one of the two white silicon things that are part of build assembly ), or, and haven't though of that until Willie said it, but I run mine fairly low wattage ( lowest it will go, shows 6w, but could run a bit higher). Will try higher wattage and see how that works. Would be interested to hear what is the wattage on those other Lemos that have leaking issues.