diff -r b195931de7fa -r 2e690e6fdc03 src/train_cmd.cpp
--- a/src/train_cmd.cpp	Fri Mar 16 17:40:31 2007 +0000
+++ b/src/train_cmd.cpp	Fri Mar 16 21:42:11 2007 +0000
@@ -1744,7 +1744,7 @@
 	if (CheckTrainStoppedInDepot(v) < 0) return_cmd_error(STR_TRAIN_MUST_BE_STOPPED);
 
 	/* Check cargo */
-	if (new_cid > NUM_CARGO) return CMD_ERROR;
+	if (new_cid >= NUM_CARGO) return CMD_ERROR;
 
 	SET_EXPENSES_TYPE(EXPENSES_TRAIN_RUN);