--- ../xmp-2.5.1-orig/src/player/player.c	2007-12-05 21:24:42 +0900
+++ src/player/player.c	2007-12-15 01:29:40 +0900
@@ -722,7 +722,7 @@
     }
 
     /* Do tone portamento */
-    if (TEST(TONEPORTA) || TEST_PER(TONEPORTA)) {
+    if (t && (TEST(TONEPORTA) || TEST_PER(TONEPORTA))) {
 	xc->period += xc->s_sgn * xc->s_val;
 	if ((xc->s_sgn * xc->s_end) < (xc->s_sgn * xc->period)) {
 	    xc->period = xc->s_end;