Combine dry mustard, salt, white pepper, and ground ginger; mix well and rub into roast. Place roast on rack in a shallow roasting pan. Insert meat thermometer so bulb is in center of thickest part of roast.

Cook, uncolvered, in a 325-degree oven for 35-40 minutes per pound or till meat thermometer registers 170 degrees, basting with glaze every 10 minutes during the last 30 minutes of cooking time. Let roast stand 10 minutes before carving to allow juices to set.

For Glaze: In a medium saucepan combine orange marmalade, corn syrup, lemon juice, dry mustard and ground ginger. Cook over medium heat for 5 minutes, stirring frequently.