Melt butter in saucepan over medium heat; saute' shallots for 5 minutes, add scallops, and cook for 1 minute.
Add wine, thyme, and curry powder, cover, then reduce heat and simmer for about 5 minutes. With slotted spoon, remove scallops to warmed serving dish.
Raise heat to bring liquid to a boil and cook until reuced by half. Lower heat then combine 1 tbs. yoghurt with cornstarch and blend with remaining yoghurt. Add to sauce, heat, stir for 2 minutes. Pour sauce over warm scallops and serve immediatly.