diff --git a/activemq-core/src/main/java/org/apache/activemq/store/kahadb/MessageDatabase.java b/activemq-core/src/main/java/org/apache/activemq/store/kahadb/MessageDatabase.java
index 9535a8317f..de9e4d453e 100644
--- a/activemq-core/src/main/java/org/apache/activemq/store/kahadb/MessageDatabase.java
+++ b/activemq-core/src/main/java/org/apache/activemq/store/kahadb/MessageDatabase.java
@@ -1754,7 +1754,6 @@ public class MessageDatabase extends ServiceSupport implements BrokerServiceAwar
                             Math.max(rc.orderIndex.nextMessageId, nextMessageId);
                 }
             }
-
         }
 
         if (metadata.version < VERSION) {
@@ -1769,10 +1768,10 @@ public class MessageDatabase extends ServiceSupport implements BrokerServiceAwar
         if (sequences == null) {
             sequences = new SequenceSet();
             sequences.add(messageSequence);
-            sd.ackPositions.put(tx, subscriptionKey, sequences);
+            sd.ackPositions.add(tx, subscriptionKey, sequences);
         } else {
             sequences.add(messageSequence);
-            sd.ackPositions.add(tx, subscriptionKey, sequences);
+            sd.ackPositions.put(tx, subscriptionKey, sequences);
         }
 
         Long count = sd.messageReferences.get(messageSequence);
@@ -1789,10 +1788,10 @@ public class MessageDatabase extends ServiceSupport implements BrokerServiceAwar
         if (sequences == null) {
             sequences = new SequenceSet();
             sequences.add(messageSequence);
-            sd.ackPositions.put(tx, subscriptionKey, sequences);
+            sd.ackPositions.add(tx, subscriptionKey, sequences);
         } else {
             sequences.add(messageSequence);
-            sd.ackPositions.add(tx, subscriptionKey, sequences);
+            sd.ackPositions.put(tx, subscriptionKey, sequences);
         }
 
         Long count = sd.messageReferences.get(messageSequence);
@@ -1811,10 +1810,10 @@ public class MessageDatabase extends ServiceSupport implements BrokerServiceAwar
             if (sequences == null) {
                 sequences = new SequenceSet();
                 sequences.add(new Sequence(messageSequence, messageSequence + 1));
-                sd.ackPositions.put(tx, subscriptionKey, sequences);
+                sd.ackPositions.add(tx, subscriptionKey, sequences);
             } else {
                 sequences.add(new Sequence(messageSequence, messageSequence + 1));
-                sd.ackPositions.add(tx, subscriptionKey, sequences);
+                sd.ackPositions.put(tx, subscriptionKey, sequences);
             }
 
             Long count = sd.messageReferences.get(messageSequence);
@@ -1875,12 +1874,12 @@ public class MessageDatabase extends ServiceSupport implements BrokerServiceAwar
      * @param sequenceId
      * @throws IOException
      */
-    private void removeAckLocation(Transaction tx, StoredDestination sd, String subscriptionKey, Long sequenceId) throws IOException {
+    private void removeAckLocation(Transaction tx, StoredDestination sd, String subscriptionKey, Long messageSequence) throws IOException {
         // Remove the sub from the previous location set..
-        if (sequenceId != null) {
+        if (messageSequence != null) {
             SequenceSet range = sd.ackPositions.get(tx, subscriptionKey);
             if (range != null && !range.isEmpty()) {
-                range.remove(sequenceId);
+                range.remove(messageSequence);
                 if (!range.isEmpty()) {
                     sd.ackPositions.put(tx, subscriptionKey, range);
                 } else {
@@ -1888,18 +1887,18 @@ public class MessageDatabase extends ServiceSupport implements BrokerServiceAwar
                 }
 
                 // Check if the message is reference by any other subscription.
-                Long count = sd.messageReferences.get(sequenceId);
+                Long count = sd.messageReferences.get(messageSequence);
                 long references = count.longValue() - 1;
                 if (references > 0) {
-                    sd.messageReferences.put(sequenceId, Long.valueOf(references));
+                    sd.messageReferences.put(messageSequence, Long.valueOf(references));
                     return;
                 } else {
-                    sd.messageReferences.remove(sequenceId);
+                    sd.messageReferences.remove(messageSequence);
                 }
 
                 // Find all the entries that need to get deleted.
                 ArrayList<Entry<Long, MessageKeys>> deletes = new ArrayList<Entry<Long, MessageKeys>>();
-                sd.orderIndex.getDeleteList(tx, deletes, sequenceId);
+                sd.orderIndex.getDeleteList(tx, deletes, messageSequence);
 
                 // Do the actual deletes.
                 for (Entry<Long, MessageKeys> entry : deletes) {