--- a/date.c	Tue Aug 22 15:23:25 2006 +0000
+++ b/date.c	Tue Aug 22 15:33:35 2006 +0000
@@ -202,7 +202,7 @@
 	for (i = daytick; i < total; i += DAY_TICKS) {
 		Vehicle *v = GetVehicle(i);
 
-		if (v->type != 0) _on_new_vehicle_day_proc[v->type - 0x10](v);
+		if (IsValidVehicle(v)) _on_new_vehicle_day_proc[v->type - 0x10](v);
 	}
 }