diff -Naur --exclude Makefile --exclude info wfdb-10.5.0/doc/wpg-src/wpg0.tex wfdb-10.5.1/doc/wpg-src/wpg0.tex
--- wfdb-10.5.0/doc/wpg-src/wpg0.tex	2010-03-17 13:15:52.000000000 -0400
+++ wfdb-10.5.1/doc/wpg-src/wpg0.tex	2010-03-19 23:57:18.000000000 -0400
@@ -8881,6 +8881,13 @@
 changes that may not be described here.
 
 @unnumberedsec WFDB 10.5
+@unnumberedsubsec Changes in version 10.5.1 (19 March 2010)
+
+In version 10.5.0, signals in formats 80 and 160 with amplitudes of 0 were
+incorrectly treated as invalid by @code{getframe()} and @code{getvec()}.
+Thanks to Isaac Henry for reporting this problem, which has been corrected in
+@file{lib/signal.c}.
+
 @unnumberedsubsec Changes in version 10.5.0 (16 March 2010)
 
 The WFDB library now supports signals with 24 and 32 bits of precision, using
diff -Naur --exclude Makefile --exclude info wfdb-10.5.0/lib/signal.c wfdb-10.5.1/lib/signal.c
--- wfdb-10.5.0/lib/signal.c	2010-03-13 12:27:33.000000000 -0500
+++ wfdb-10.5.1/lib/signal.c	2010-03-19 23:48:50.000000000 -0400
@@ -1745,14 +1745,14 @@
 		break;
 	      case 80:	/* 8-bit offset binary amplitudes */
 		*vector = v = r80(ig);
-		if (v == 0)
+		if (v == -1 << 7)
 		    *vector = gvpad ? is->samp : WFDB_INVALID_SAMPLE;
 		else
 		    is->samp = *vector;
 		break;
 	      case 160:	/* 16-bit offset binary amplitudes */
 		*vector = v = r160(ig);
-		if (v == 0)
+		if (v == -1 << 15)
 		    *vector = gvpad ? is->samp : WFDB_INVALID_SAMPLE;
 		else
 		    is->samp = *vector;
diff -Naur --exclude Makefile --exclude info wfdb-10.5.0/lib/wfdb.h wfdb-10.5.1/lib/wfdb.h
--- wfdb-10.5.0/lib/wfdb.h	2010-03-17 14:28:39.000000000 -0400
+++ wfdb-10.5.1/lib/wfdb.h	2010-03-19 23:58:10.000000000 -0400
@@ -33,7 +33,7 @@
 /* WFDB library version. */
 #define WFDB_MAJOR   10
 #define WFDB_MINOR   5
-#define WFDB_RELEASE 0
+#define WFDB_RELEASE 1
 #define WFDB_NETFILES 1	/* if 1, library includes code for HTTP, FTP clients */
 #define WFDB_NETFILES_LIBCURL 1
 
diff -Naur --exclude Makefile --exclude info wfdb-10.5.0/NEWS wfdb-10.5.1/NEWS
--- wfdb-10.5.0/NEWS	2010-03-17 15:36:00.000000000 -0400
+++ wfdb-10.5.1/NEWS	2010-03-20 00:31:43.000000000 -0400
@@ -1,3 +1,9 @@
+10.5.1 (19 March 2010):
+       In version 10.5.0, signals in formats 80 and 160 with amplitudes of 0
+       were incorrectly treated as invalid by getframe() and getvec().  Thanks
+       to Isaac Henry for reporting this problem, which has been corrected in
+       signal.c.
+
 10.5.0 (16 March 2010):
 	The WFDB library now supports signals with 24 and 32 bits of precision,
 	using new formats 24 and 32, and WFDB applications 'wrsamp' and 'xform'