--- src/core/org/apache/jmeter/control/GenericController.java	(revision 1170850)
+++ src/core/org/apache/jmeter/control/GenericController.java	(working copy)
@@ -333,6 +333,19 @@ 
          */
         iterationListeners.addFirst(lis);
     }
+    
+    /**
+     * Remove listener
+     */
+    public void removeIterationListener(LoopIterationListener iterationListener) {
+        for (Iterator iterator = iterationListeners.iterator(); iterator.hasNext();) {
+            LoopIterationListener listener = (LoopIterationListener) iterator.next();
+            if(listener == iterationListener)
+            {
+                iterator.remove();
+            }
+        }
+    }
 
     protected void fireIterEvents() {
         if (isFirst()) {
--- src/core/org/apache/jmeter/control/Controller.java	(revision 1166194)
+++ src/core/org/apache/jmeter/control/Controller.java	(working copy)
@@ -56,4 +56,10 @@ 
      * Called to initialize a controller at the beginning of a test iteration.
      */
     public void initialize();
+
+    /**
+     * Unregister IterationListener
+     * @param iterationListener {@link LoopIterationListener}
+     */
+    public void removeIterationListener(LoopIterationListener iterationListener);
 }
--- src/core/org/apache/jmeter/threads/AbstractThreadGroup.java	(revision 1166194)
+++ src/core/org/apache/jmeter/threads/AbstractThreadGroup.java	(working copy)
@@ -111,6 +111,11 @@ 
     public void addIterationListener(LoopIterationListener lis) {
         getSamplerController().addIterationListener(lis);
     }
+    
+    /** {@inheritDoc} */
+    public void removeIterationListener(LoopIterationListener iterationListener) {
+        getSamplerController().removeIterationListener(iterationListener);
+    }
 
     /** {@inheritDoc} */
     public void initialize() {
--- src/core/org/apache/jmeter/threads/JMeterThread.java	(revision 1171011)
+++ src/core/org/apache/jmeter/threads/JMeterThread.java	(working copy)
@@ -123,6 +123,9 @@ 
 
     private volatile Sampler currentSampler;
 
+    private LoopIterationListener iterationListener;
+
+
     public JMeterThread(HashTree test, JMeterThreadMonitor monitor, ListenerNotifier note) {
         this.monitor = monitor;
         threadVars = new JMeterVariables();
@@ -496,7 +499,8 @@ 
             threadContext.setSamplingStarted(true);
         }
         controller.initialize();
-        controller.addIterationListener(new IterationListener());
+        this.iterationListener = new IterationListener();
+        controller.addIterationListener(iterationListener);
         if (!startEarlier) {
             threadContext.setSamplingStarted(true);
         }
@@ -523,6 +527,7 @@ 
         if (gp != null){// check there is a GUI
             gp.getMainFrame().updateCounts();
         }
+        controller.removeIterationListener(iterationListener);
     }
 
     private static class ThreadListenerTraverser implements HashTreeTraverser {
@@ -708,7 +713,7 @@ 
         }
     }
 
-    private void notifyTestListeners() {
+    void notifyTestListeners() {
         threadVars.incIteration();
         Iterator<TestListener> iter = testListeners.iterator();
         while (iter.hasNext()) {
--- src/core/org/apache/jmeter/threads/JMeterContext.java	(revision 1171011)
+++ src/core/org/apache/jmeter/threads/JMeterContext.java	(working copy)
@@ -65,6 +65,7 @@ 
         samplingStarted = false;
         threadNum = 0;
         readBuffer = null;
+        thread = null;
     }
 
     /**