diff -Naur TiMidity++-2.13.2/timidity/instrum.c TiMidity++-2.13.2.new/timidity/instrum.c
--- TiMidity++-2.13.2/timidity/instrum.c	2004-05-30 23:48:11.000000000 +0200
+++ TiMidity++-2.13.2.new/timidity/instrum.c	2009-08-11 15:09:30.977041000 +0200
@@ -1465,8 +1465,9 @@
     clear_magic_instruments();
 
     /* Free soundfont instruments */
-    while(i--)
+    while(i > 0)
     {
+	i--;
 	/* Note that bank[*]->tone[j].instrument may pointer to
 	   bank[0]->tone[j].instrument. See play_midi_load_instrument()
 	   at playmidi.c for the implementation */