Combine first 3 ingredients in a bowl. Heat oil in a large skillet over medium-high heat. Add shrimp; cook 3 to 4 minutes or until pink, stirring occasionally. (Shrimp will not be cooked through.) Remove from skillet; set aside.
Add bell pepper, curry paste, and curry powder to skillet. Cook for 2 minutes, stirring constantly. Stir in coconut milk, soy sauce, and brown sugar. Cook for 3 minutes or until curry paste dissolves, stirring constantly.
Stir in shrimp; cook 2 minutes. Remove from heat. Stir in cilantro, and serve immediately in shallow bowls over hot cooked rice.
Keep uncooked shrimp in the freezer. To thaw and peel frozen shrimp, place in a bowl of cold water for 15 minutes, occasionally breaking up frozen clumps with your hands. After 15 minutes, the shrimp will be thawed enough to peel. By the time you finish peeling them, they will have thawed completely.