Kevin, you did say the wood was on fire, right? Either you got a drier chunk, or you have have a hotter spot on your element. Might try moving your wood to a different location in the box. On my 3D, dead middle is the hottest spot, so I tend to keep wood toward the back or front. All I can say is that it does happen sometimes, even with really good wood! Those elements are really powerful, and get very hot at startup!