we had one of the early stoves and it did the same thing. Woodstock replaced the stove and the newer version has that area beefed up with welds. During secondary burns we could see flame in that area as if air was leaking in. Stuff some gasket material in there and you should be good to go. Moving that 750 lb behemoth was pita. The only reason we went for the rebuild was the smoke smell from the door frame.