Combine tamarind and hot water. Mix in well and let stand for 30 minutes. Saute shallots, ginger and red pepper flakes in oil for 3 minutes. Strain tamarind liquid into the shallot mixture. Discard the pulp. Add soy sauces and sugar. Bring to a simmer. Add peanut butter and stir until smooth. Brush spareribs generously with vinegar. Let stand for 2 hours. Place ribs on grill or in 350 degree oven. Cook for 1 1/2 hours basting with the peanut sauce every half an hour. Serve ribs with remaining sauce.