diff -r f67d4fd5ed5d -r 2e120d0bd632 src/oldloader.cpp
--- a/src/oldloader.cpp	Sat Apr 05 21:45:05 2008 +0000
+++ b/src/oldloader.cpp	Sat Apr 05 23:36:54 2008 +0000
@@ -345,8 +345,8 @@
 		 * (loading) order which causes assertions and the like later on.
 		 */
 		if (!IsPlayerBuildableVehicleType(v) ||
-				(v->IsPrimaryVehicle() && v->current_order.type == OT_NOTHING)) {
-			v->current_order.type = OT_DUMMY;
+				(v->IsPrimaryVehicle() && v->current_order.IsType(OT_NOTHING))) {
+			v->current_order.MakeDummy();
 		}
 
 		FOR_ALL_VEHICLES_FROM(u, v->index + 1) {