--- ../xmp-2.4.1-orig/src/player/mixer.c	2007-10-29 11:44:26 +0900
+++ src/player/mixer.c	2007-11-20 19:28:29 +0900
@@ -232,11 +232,13 @@
     if (vi->vol) {
 	oldvol = vi->vol * (0x80 - vi->pan);
 	newvol = vol * (0x80 - pan);
-	vi->sright -= vi->sright / oldvol * newvol;
+	if (oldvol)
+	    vi->sright -= vi->sright / oldvol * newvol;
 
 	oldvol = vi->vol * (0x80 + vi->pan);
 	newvol = vol * (0x80 + pan);
-	vi->sleft -= vi->sleft / oldvol * newvol;
+	if (oldvol)
+	    vi->sleft -= vi->sleft / oldvol * newvol;
     }
 
     if (!buf) {