I have trashed two gaskets in to weeks on my XL. What is the ultimate pizza setup? I have a platesetter,GS hanger and a 12 inch pizza stone. Last week when the egg got around 500 degrees the bands loosened a bit creating a gap in the rear resulting in blown gasket. Last night with new gasket, plate setter on top of fire ring feet up, 4 fire brick 1/4s supporting the pizza stone egg got around 500 first pizza went ok, second pizza with egg still at 500 took pizza off everything ok 5minutes passed opened dome, gasket fussed and burnt. I have a new Nomex gasket on the way but this shouldn't have happened. What am I missing?