diff --git a/lib/OpenLayers/Control/PanZoom.js b/lib/OpenLayers/Control/PanZoom.js
index e92036059b..2f998a6625 100644
--- a/lib/OpenLayers/Control/PanZoom.js
+++ b/lib/OpenLayers/Control/PanZoom.js
@@ -163,6 +163,7 @@ OpenLayers.Control.PanZoom = OpenLayers.Class(OpenLayers.Control, {
     _removeButton: function(btn) {
         OpenLayers.Event.stopObservingElement(btn);
         btn.map = null;
+        btn.getSlideFactor = null;
         this.div.removeChild(btn);
         OpenLayers.Util.removeItem(this.buttons, btn);
     },
diff --git a/tests/manual/memory/PanZoom-2323.html b/tests/manual/memory/PanZoom-2323.html
new file mode 100644
index 0000000000..de629a69db
--- /dev/null
+++ b/tests/manual/memory/PanZoom-2323.html
@@ -0,0 +1,41 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+  <head>
+    <title>Memory Test - PanZoom.getSlideFactor</title>
+    <style type="text/css">
+        body {
+            font-size: 0.8em;
+        }
+        p {
+            padding-top: 1em;
+        }
+        #map {
+            width: 256px;
+            height: 256px;
+            border: 1px solid black;
+        }
+    </style>
+
+    <script src="../../../lib/Firebug/firebug.js"></script>
+    <script src="../../../lib/OpenLayers.js"></script>
+    <script type="text/javascript">
+        var map;
+        var layer;
+        
+        function init(){
+            map = new OpenLayers.Map('map');
+        }
+    </script>
+  </head>
+  <body onload="init()">
+    <h1 id="title">Memory Test - PanZoom.getSlideFactor</h1>
+    <pre id="status"></pre>
+    <div id="map"></div>
+    <p>
+    This test is a memory leak test for: PanZoom.getSlideFactor.
+    </p>
+    <p>
+    Run this test in IE6/7 with <a href="http://blogs.msdn.com/gpde/pages/javascript-memory-leak-detector-v2.aspx">JavaScript Memory Leak Detector v2</a>
+    and watch it identify a leak unless this is fixed.
+    </p>
+  </body>
+</html>
