diff --git a/lib/opengd77base_codeplug.cc b/lib/opengd77base_codeplug.cc
index 6545e48c..7a56420c 100644
--- a/lib/opengd77base_codeplug.cc
+++ b/lib/opengd77base_codeplug.cc
@@ -1469,27 +1469,31 @@ OpenGD77BaseCodeplug::ZoneElement::setName(const QString &name) {
   writeASCII(Offset::name(), name, Limit::nameLength(), 0xff);
 }
 
+
 bool
 OpenGD77BaseCodeplug::ZoneElement::hasMember(unsigned n) const {
   if (n >= Limit::memberCount())
     return false;
-  return (0 != member(n));
+  return 0 != getUInt16_le(Offset::channels() + Offset::betweenChannels()*n);
 }
+
 unsigned
 OpenGD77BaseCodeplug::ZoneElement::member(unsigned n) const {
   if (n >= Limit::memberCount())
     return 0;
-  return getUInt16_le(Offset::channels()+Offset::betweenChannels()*n);
+  return getUInt16_le(Offset::channels() + Offset::betweenChannels()*n)-1;
 }
+
 void
 OpenGD77BaseCodeplug::ZoneElement::setMember(unsigned n, unsigned idx) {
   if (n >= Limit::memberCount())
     return;
-  setUInt16_le(Offset::channels()+Offset::betweenChannels()*n, idx);
+  setUInt16_le(Offset::channels() + Offset::betweenChannels()*n, idx+1);
 }
+
 void
 OpenGD77BaseCodeplug::ZoneElement::clearMember(unsigned n) {
-  setMember(n, 0);
+  setUInt16_le(Offset::channels() + Offset::betweenChannels()*n, 0);
 }
 
 
@@ -2161,12 +2165,12 @@ OpenGD77BaseCodeplug::GroupListElement::hasContactIndex(unsigned int i) const {
 
 unsigned int
 OpenGD77BaseCodeplug::GroupListElement::contactIndex(unsigned int i) const {
-  return getUInt16_le(Offset::contacts() + i*Offset::betweenContacts())-1;
+  return getUInt16_le(Offset::contacts() + i*Offset::betweenContacts()) - 1;
 }
 
 void
 OpenGD77BaseCodeplug::GroupListElement::setContactIndex(unsigned int i, unsigned int contactIdx) {
-  setUInt16_le(Offset::contacts() + i*Offset::betweenContacts(), contactIdx+1);
+  setUInt16_le(Offset::contacts() + i*Offset::betweenContacts(), contactIdx + 1);
 }
 
 void
diff --git a/lib/opengd77base_codeplug.hh b/lib/opengd77base_codeplug.hh
index d2c64ea4..4a36ad6c 100644
--- a/lib/opengd77base_codeplug.hh
+++ b/lib/opengd77base_codeplug.hh
@@ -805,12 +805,11 @@ public:
     /** Sets the name of the zone. */
     virtual void setName(const QString &name);
 
-    /** Returns @c true if a member is stored at the given index.
-     * That is, if the index is not 0. */
+    /** Returns @c true if a member is stored at the given index. */
     virtual bool hasMember(unsigned n) const;
-    /** Returns the n-th member index (+1). */
+    /** Returns the n-th member index. */
     virtual unsigned member(unsigned n) const;
-    /** Sets the n-th member index (+1). */
+    /** Sets the n-th member index. */
     virtual void setMember(unsigned n, unsigned idx);
     /** Clears the n-th member index. */
     virtual void clearMember(unsigned n);