Gregg, you're right. I guess this should have been made more clear - the combustion I've experienced only occurs as the smoker passes around 180+. Low-temp smokes have never produced this problem. I know many don't worry about it, but I do. I never experienced this in my #1, but definitely have in the #2. The problem it creates is a) really nasty-smelling, dark smoke, and b) severely shortened smoke time (the wood burns up too fast, instead of smoldering to a slow death). I don't care for either of these. Thin blue smoke for me!