fix strange bug with a const reference to a Vector

main/Scene-load.cc

@@ -395,10 +395,10 @@ ShapeRef Scene::processCyl(refptr<Node> node)
     {
         if      ( typeid(**it) == typeid(SizeNode) )
         {
-            const Vector & v = *(*it)->getVector();
-            radius1 = v[0];
-            radius2 = v[1];
-            height = v[2];
+            refptr<Vector> v = (*it)->getVector();
+            radius1 = (*v)[0];
+            radius2 = (*v)[1];
+            height = (*v)[2];
         }
         else if ( (*it)->isMaterial() )
         {