Cut ribs into 2-rib sections.
Place ribs in a plastic bag set into a shallow dish.
For marinade, combine soy sauce, brown sugar, water, sherry, pineapple juice, gingerroot, and garlic.
Pour marinade over ribs.
Marinate in the refrigerator several hours or overnight, turning bag occasionally.
Drain ribs, reserving marinade.
Place ribs, meaty side up, in center of the cooking grill.
Grill 1 to 1 1/2 hours or till tender, brushing with reserved marinade during the last 15 minutes of grilling time.