diff --git a/gsw_check_functions.c b/gsw_check_functions.c
index 843d04d..4b96423 100644
--- a/gsw_check_functions.c
+++ b/gsw_check_functions.c
@@ -538,9 +538,9 @@ report(char *funcname, char *varname, gsw_error_info *errs)
 	if (strcmp(funcname, varname)) {
 	    msglen += 5;
 	    if (msglen > 62) {
-		k = strlen(varname) - (msglen - 62);
+		k = msglen - 62;
 		strcat(message, " (..");
-		strncat(message, varname, k);
+		strcat(message, varname+k);
 	    } else {
 		strcat(message, " (");
 		strcat(message, varname);
diff --git a/gsw_oceanographic_toolbox.c b/gsw_oceanographic_toolbox.c
index eeee4c9..0ff106c 100644
--- a/gsw_oceanographic_toolbox.c
+++ b/gsw_oceanographic_toolbox.c
@@ -1,6 +1,6 @@
 /*
 **  $Id: gsw_oceanographic_toolbox-head,v c61271a7810d 2016/08/19 20:04:03 fdelahoyde $
-**  Version: 3.05.0-3
+**  Version: 3
 **
 **  This is a translation of the original f90 source code into C
 **  by the Shipboard Technical Support Computing Resources group
@@ -3923,8 +3923,13 @@ p_sequence(double p1, double p2, double max_dp_i, double *pseq, int *nps)
 
 	if (nps != NULL) *nps = n;
 
-	for (i=1; i<=n; i++)
-	    pseq[i-1] = p1+pstep*i;
+	/*
+	! Generate the sequence ensuring that the value of p2 is exact to
+	! avoid round-off issues, ie. don't do "pseq = p1+pstep*(i+1)".
+	*/
+	for (i=0; i<n; i++)
+	    pseq[i] = p2-pstep*(n-1-i);
+
 }
 /*
 !==========================================================================
@@ -7859,20 +7864,31 @@ rr68_interp_section(int sectnum, double *sa, double *ct, double *p, int mp,
 	    for (i=0; i<nsect; i++) {
 		ip_1[i] = floor(ip_sect[i]);
 		ip_2[i] = ceil(ip_sect[i]);
+		if (ip_1[i] == ip_2[i])
+		    ip_2[i] = ip_1[i] + 1;
 		ip_3[i] = ip_2[i] + 1;
 		ip_4[i] = ip_3[i] + 1;
 	    }
 	} else if (sectnum == 0) {  /* central */
 	    for (i=0; i<nsect; i++) {
 		ip_2[i] = floor(ip_sect[i]);
-		ip_1[i] = ip_2[i] - 1;
 		ip_3[i] = ceil(ip_sect[i]);
+		if (ip_2[i] == ip_3[i])
+		    ip_2[i] = ip_3[i] - 1;
+		ip_1[i] = ip_2[i] - 1;
+		if (ip_1[i] < 0) {
+		    ip_1[i] = 0;
+		    ip_2[i] = 1;
+		    ip_3[i] = 2;
+	        }
 		ip_4[i] = ip_3[i] + 1;
 	    }
 	} else if (sectnum > 0) {  /* deep */
 	    for (i=0; i<nsect; i++) {
 		ip_1[i] = ceil(ip_sect[i]);
 		ip_2[i] = floor(ip_sect[i]);
+		if (ip_1[i] == ip_2[i])
+		    ip_2[i] = ip_1[i] - 1;
 		ip_3[i] = ip_2[i] - 1;
 		ip_4[i] = ip_3[i] - 1;
 	    }
diff --git a/toolbox/gsw_geo_strf_dyn_height.c b/toolbox/gsw_geo_strf_dyn_height.c
index a7c04c8..d983449 100644
--- a/toolbox/gsw_geo_strf_dyn_height.c
+++ b/toolbox/gsw_geo_strf_dyn_height.c
@@ -301,6 +301,11 @@ p_sequence(double p1, double p2, double max_dp_i, double *pseq, int *nps)
 
 	if (nps != NULL) *nps = n;
 
-	for (i=1; i<=n; i++)
-	    pseq[i-1] = p1+pstep*i;
+	/*
+	! Generate the sequence ensuring that the value of p2 is exact to
+	! avoid round-off issues, ie. don't do "pseq = p1+pstep*(i+1)".
+	*/
+	for (i=0; i<n; i++)
+	    pseq[i] = p2-pstep*(n-1-i);
+
 }
diff --git a/toolbox/gsw_rr68_interp_sa_ct.c b/toolbox/gsw_rr68_interp_sa_ct.c
index bb6bcf9..44eb174 100644
--- a/toolbox/gsw_rr68_interp_sa_ct.c
+++ b/toolbox/gsw_rr68_interp_sa_ct.c
@@ -178,20 +178,31 @@ rr68_interp_section(int sectnum, double *sa, double *ct, double *p, int mp,
 	    for (i=0; i<nsect; i++) {
 		ip_1[i] = floor(ip_sect[i]);
 		ip_2[i] = ceil(ip_sect[i]);
+		if (ip_1[i] == ip_2[i])
+		    ip_2[i] = ip_1[i] + 1;
 		ip_3[i] = ip_2[i] + 1;
 		ip_4[i] = ip_3[i] + 1;
 	    }
 	} else if (sectnum == 0) {  /* central */
 	    for (i=0; i<nsect; i++) {
 		ip_2[i] = floor(ip_sect[i]);
-		ip_1[i] = ip_2[i] - 1;
 		ip_3[i] = ceil(ip_sect[i]);
+		if (ip_2[i] == ip_3[i])
+		    ip_2[i] = ip_3[i] - 1;
+		ip_1[i] = ip_2[i] - 1;
+		if (ip_1[i] < 0) {
+		    ip_1[i] = 0;
+		    ip_2[i] = 1;
+		    ip_3[i] = 2;
+	        }
 		ip_4[i] = ip_3[i] + 1;
 	    }
 	} else if (sectnum > 0) {  /* deep */
 	    for (i=0; i<nsect; i++) {
 		ip_1[i] = ceil(ip_sect[i]);
 		ip_2[i] = floor(ip_sect[i]);
+		if (ip_1[i] == ip_2[i])
+		    ip_2[i] = ip_1[i] - 1;
 		ip_3[i] = ip_2[i] - 1;
 		ip_4[i] = ip_3[i] - 1;
 	    }