Combine pork and shrimp. Soak mushrooms in warm water for 20 minutes. Remove the stems and chop the caps. Soak bean threads in warm water for 20 minutes, cut into 1 inch lengths. Add mushrooms, bean threads, onion, carrot, bean sprouts, black pepper, fish sauce to the pork/shrimp mixture. Mix well. Set aside for 15 minutes to allow flavors to blend. Dillute sugar in warm water. Place rice paper on flat surface. Brush with water until pliable. Place 2 teaspoons filling near the edge of paper, and fold over the filling. Fold the right & left sides over to enclose filling. Continue to roll, and seal. Deep fry a few at a time, about 15 minutes, serve.