I can't imagine where else there could be a problem. The unit is new, running less than a month now. All around the base is still very well sealed with silicon, the damper flap is moving freely, there's no creosote keeping the firebox door from sealing, the flue is still sealed shut (haven't opened it yet), the ash auger tube is sealed shut (made sure the gasket was in place), the anti-rollback device seals shut when the outer door is closed. It's been windy before with no ill effects, so I'm at a loss right now. I'll toss a board over the chimney while it's firing to see if I see smoke elsewhere, but I highly doubt I will. Perhaps it's time to call Heatmor...