Combine oats, nuts, brown sugar and margarine; press onto bottom of 23 cm springform pan. Bake at 180ºC ., 15 minutes. Combine cream cheese, granulated sugar and 2 T flour, mixing at medium speed on electric mixer until well blended. Add eggs, one at a time, mixing well after each addition. Blend in sour cream and rum; mix well. Pour over crust. Cut margarine into combined remaining flour and brown sugar until mixture resembles coarse crumbs. Stir in raisins, nuts and oats. Sprinkle over cream cheese mixture. Bake at 180ºC ., 50 minutes. Loosen cake from rim of pan; cool before removing rim of pan.