diff -urN alsa-lib-1.0.23-orig/src/pcm/pcm.c alsa-lib-1.0.23/src/pcm/pcm.c
--- alsa-lib-1.0.23-orig/src/pcm/pcm.c	2010-04-16 20:11:05 +0900
+++ alsa-lib-1.0.23/src/pcm/pcm.c	2010-06-16 13:43:10 +0900
@@ -2672,7 +2672,8 @@
 	    dst_area->step == (unsigned int) width) {
 		size_t bytes = samples * width / 8;
 		samples -= bytes * 8 / width;
-		memcpy(dst, src, bytes);
+		if (dst != src)
+			memcpy(dst, src, bytes);
 		if (samples == 0)
 			return 0;
 	}