--- a/src/train_cmd.cpp	Mon Mar 17 21:49:14 2008 +0000
+++ b/src/train_cmd.cpp	Mon Mar 17 21:50:53 2008 +0000
@@ -290,6 +290,8 @@
 
 	/* recalculate cached weights and power too (we do this *after* the rest, so it is known which wagons are powered and need extra weight added) */
 	TrainCargoChanged(v);
+
+	InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
 }
 
 enum AccelType {