The fact that wheat (durum wheat has the same antigens) is positive and gluten is negative is a very normal situation. Wheat proteins consist of gluten and wheat specific proteins which are investigated with two completely different tests. It is possible to be sensitized to either of them or both of them. The same applies to kamut and other cereals: You can show no reaction to gluten but react to different sorts of flour if you have a hypersensitivity to the specific proteins of the cereal.