Preheat oven to 350˚F.

In a small saucepan, melt cream cheese and 1/2 stick butter together on low heat.

In a separate saucepan add remaining 1/2 stick butter, onion, bell pepper, garlic and mushrooms. Sauté until vegetables are tender. Add shrimp, salt, cayenne pepper and black pepper. Sauté until shrimp are pink. Add rice and cream cheese mixture; mix well. Gently spoon in crabmeat. Pour into a 3 quart casserole dish. Sprinkle with cracker crumbs. Bake until golden and bubbly, about 30 minutes. Serve hot.