diff --git a/src/net/java/sip/communicator/impl/gui/main/call/CallManager.java b/src/net/java/sip/communicator/impl/gui/main/call/CallManager.java
index 3f052c674..5c1460707 100644
--- a/src/net/java/sip/communicator/impl/gui/main/call/CallManager.java
+++ b/src/net/java/sip/communicator/impl/gui/main/call/CallManager.java
@@ -100,7 +100,7 @@ public void run()
                     .hasEnabledVideoFormat(sourceCall.getProtocolProvider());
             final ReceivedCallDialog receivedCallDialog
                 = new ReceivedCallDialog(sourceCall, isVideoCall,
-                    (CallManager.getActiveCalls().size() > 0));
+                    (CallManager.getInProgressCalls().size() > 0));
 
             receivedCallDialog.setVisible(true);
 
@@ -279,7 +279,7 @@ private static void answerCall(Call call, Call existingCall, boolean video)
     public static void answerCallInFirstExistingCall(Call call)
     {
         // Find the first existing call.
-        Iterator<Call> existingCallIter = getActiveCalls().iterator();
+        Iterator<Call> existingCallIter = getInProgressCalls().iterator();
         Call existingCall
             = existingCallIter.hasNext() ? existingCallIter.next() : null;
 
@@ -1107,6 +1107,31 @@ public static Collection<Call> getActiveCalls()
         return activeCalls.keySet();
     }
 
+    /**
+     * Returns a collection of all currently in progress calls.
+     *
+     * @return a collection of all currently in progress calls.
+     */
+    public static Collection<Call> getInProgressCalls()
+    {
+        Set<Call> calls = activeCalls.keySet();
+        ArrayList<Call> inProgressCalls = new ArrayList<Call>(calls.size()); 
+        Iterator<Call> it = calls.iterator();
+        Call tmpCall;
+
+        while(it.hasNext())
+        {
+            tmpCall = it.next();
+            if(tmpCall.getCallState() == CallState.CALL_IN_PROGRESS)
+            {
+                inProgressCalls.add(tmpCall);
+            }
+        }
+
+        //return calls;
+        return inProgressCalls;
+    }
+
     /**
      * Returns the <tt>CallContainer</tt> corresponding to the given
      * <tt>call</tt>. If the call has been finished and no active
diff --git a/src/net/java/sip/communicator/impl/gui/main/call/CallPanel.java b/src/net/java/sip/communicator/impl/gui/main/call/CallPanel.java
index ce8689810..ae759a4a4 100644
--- a/src/net/java/sip/communicator/impl/gui/main/call/CallPanel.java
+++ b/src/net/java/sip/communicator/impl/gui/main/call/CallPanel.java
@@ -337,6 +337,12 @@ public CallPanel(Call call, CallContainer callWindow)
         // Adds a CallChangeListener that would receive events when a peer is
         // added or removed, or the state of the call has changed.
         call.addCallChangeListener(this);
+        Iterator<Call> calls = CallManager.getActiveCalls().iterator();
+        while(calls.hasNext())
+        {
+            calls.next().addCallChangeListener(this);
+        }
+
 
         // Adds the CallPeerConferenceListener that would listen for changes in
         // the focus state of each call peer.
@@ -495,7 +501,7 @@ public void actionPerformed(ActionEvent evt)
 
         if (buttonName.equals(MERGE_BUTTON))
         {
-            Collection<Call> calls = CallManager.getActiveCalls();
+            Collection<Call> calls = CallManager.getInProgressCalls();
 
             CallManager.mergeExistingCall(call, calls);
         }
@@ -922,7 +928,9 @@ public void callPeerRemoved(CallPeerEvent evt)
     }
 
     public void callStateChanged(CallChangeEvent evt)
-    {}
+    {
+        updateMergeButtonState();
+    }
 
     /**
      * Updates <tt>CallPeer</tt> related components to fit the new focus state.
@@ -1699,6 +1707,7 @@ public void disposeCallInfoFrame()
     public void incomingCallReceived(CallEvent event)
     {
         updateMergeButtonState();
+        event.getSourceCall().addCallChangeListener(this);
     }
 
     /**
@@ -1707,6 +1716,7 @@ public void incomingCallReceived(CallEvent event)
     public void outgoingCallCreated(CallEvent event)
     {
         updateMergeButtonState();
+        event.getSourceCall().addCallChangeListener(this);
     }
 
     /**
@@ -1715,6 +1725,16 @@ public void outgoingCallCreated(CallEvent event)
     public void callEnded(CallEvent event)
     {
         updateMergeButtonState();
+        Call evtCall = event.getSourceCall();
+        evtCall.removeCallChangeListener(this);
+        if(evtCall.equals(this.call))
+        {
+            Iterator<Call> calls = CallManager.getActiveCalls().iterator();
+            while(calls.hasNext())
+            {
+                calls.next().removeCallChangeListener(this);
+            }
+        }
     }
 
     /**
@@ -1723,7 +1743,7 @@ public void callEnded(CallEvent event)
     public void updateMergeButtonState()
     {
         Collection<Call> calls
-            = new ArrayList<Call>(CallManager.getActiveCalls());
+            = new ArrayList<Call>(CallManager.getInProgressCalls());
 
         if (calls.size() == 1)
         {
diff --git a/src/net/java/sip/communicator/impl/gui/main/call/DTMFHandler.java b/src/net/java/sip/communicator/impl/gui/main/call/DTMFHandler.java
index 126c6e505..48288720b 100644
--- a/src/net/java/sip/communicator/impl/gui/main/call/DTMFHandler.java
+++ b/src/net/java/sip/communicator/impl/gui/main/call/DTMFHandler.java
@@ -394,7 +394,7 @@ private synchronized void startSendingDtmfTone(DTMFToneInfo info)
         }
         else
         {
-            Collection<Call> activeCalls = CallManager.getActiveCalls();
+            Collection<Call> activeCalls = CallManager.getInProgressCalls();
 
             if (activeCalls != null)
             {
@@ -459,7 +459,7 @@ public synchronized void stopSendingDtmfTone()
         }
         else
         {
-            Collection<Call> activeCalls = CallManager.getActiveCalls();
+            Collection<Call> activeCalls = CallManager.getInProgressCalls();
 
             if (activeCalls != null)
             {
diff --git a/src/net/java/sip/communicator/impl/gui/main/call/TransferCallButton.java b/src/net/java/sip/communicator/impl/gui/main/call/TransferCallButton.java
index 6f31bec20..4174c0d2a 100644
--- a/src/net/java/sip/communicator/impl/gui/main/call/TransferCallButton.java
+++ b/src/net/java/sip/communicator/impl/gui/main/call/TransferCallButton.java
@@ -107,7 +107,8 @@ private void transferCall()
     private Collection<CallPeer> getTransferCallPeers()
     {
         Collection<CallPeer> transferCalls = null;
-        Iterator<Call> activeCalls = CallManager.getActiveCalls().iterator();
+        Iterator<Call> activeCalls
+            = CallManager.getInProgressCalls().iterator();
         while (activeCalls.hasNext())
         {
             Call activeCall = activeCalls.next();