This is an interesting problem. I had a problem a year ago with my bread maker which was kind of similar. The convection fan broke and the bread was burning because the heat was staying in one place. \r\n\r\nYou say the crust is thick. Does it still rise as much as it used to? Could the flour be old? Have you tried sifting the flour before you use it? Is the yeast fresh?\r\n\r\nIf you have tried everything, I would suggest contacting Panasonic directly. I think someone posted links for North American manufacturers on the Toaster Oven board.\r\n\r\nAnyway, Good luck and I hope you resolve your problem