Is there any kind of exhaust vent on the roof near the melt.Is The insulation directy below the melt in good shape.Is the thickness of the insulation the same as surounding areas.Does the insulation cover the beams in the ceiling.Is there an opening or crack in the ceiling close to the melt.Is there a heat source directly below the melt, or a lite in the attic that may stay on,heating the roof from the inside.
If the insulation is in good condittion, i cant see how it could be happening.Could be just heat building up while cooking, that passes through the insulation in the kitchen seiling.Try adding some fiberglass on top of the blown insulation, over the kithchen area.4" should do it