So my Mt Vernon has developed a ticking sound in the last few months (owned 1 year). It starts just after the stove stops feeding pellets/begins shutdown, and stops about when it goes into the cleaning/grinding sound phase. It clearly (to me) is a metal contracting/cooling thing as the pace of the ticking slows down and fades as the stove cools. So I tightened the 2 bolts that are to the left and right of the burn pot, where it attaches to the floor of the main chamber, and I discovered that indeed the bolts were a bit loose. So I tightened and the ticking stopped. A few days later, the ticking started again and the bolts were again a bit loose (about 1/2 a turn). Now, a couple months later I tighten them and the ticking doesn't stop, next day the bolts are again a bit loose. Has anyone else experienced this, and/or any suggestion on how to more permanently tighten the bolts so they wont work loose as the metal heats and cools? Thanks...