diff --git a/lib/OpenLayers/Handler/MouseWheel.js b/lib/OpenLayers/Handler/MouseWheel.js
index 060022a7ec..86bfef3707 100644
--- a/lib/OpenLayers/Handler/MouseWheel.js
+++ b/lib/OpenLayers/Handler/MouseWheel.js
@@ -66,61 +66,128 @@ OpenLayers.Handler.MouseWheel = OpenLayers.Class(OpenLayers.Handler, {
      * e - {Event} 
      */
     onWheelEvent: function(e){
-        // first check keyboard modifiers
-        if (!this.checkModifiers(e)) {
+        
+        // make sure we have a map and check keyboard modifiers
+        if (!this.map || !this.checkModifiers(e)) {
             return;
         }
-        // first determine whether or not the wheeling was inside the map
-        var inMap = false;
+        
+        // Ride up the element's DOM hierarchy to determine if it or any of 
+        //  its ancestors was: 
+        //   * specifically marked as scrollable
+        //   * one of our layer divs
+        //   * the map div
+        //
+        var overScrollableDiv = false;
+        var overLayerDiv = false;
+        var overMapDiv = false;
+        
         var elem = OpenLayers.Event.element(e);
-        while(elem != null) {
-            if (this.map && elem == this.map.div) {
-                inMap = true;
-                break;
+        while((elem != null) && !overMapDiv && !overScrollableDiv) {
+
+            if (!overScrollableDiv) {
+                try {
+                    if (elem.currentStyle) {
+                        overflow = elem.currentStyle["overflow"];
+                    } else {
+                        var style = 
+                            document.defaultView.getComputedStyle(elem, null);
+                        var overflow = style.getPropertyValue("overflow");
+                    }
+                    overScrollableDiv = ( overflow && 
+                        (overflow == "auto") || (overflow == "scroll") );
+                } catch(err) {
+                    //sometimes when scrolling in a popup, this causes 
+                    // obscure browser error
+                }
             }
+
+            if (!overLayerDiv) {
+                for(var i=0; i < this.map.layers.length; i++) {
+                    if (elem == this.map.layers[i].div) { 
+                        overLayerDiv = true;
+                        break;
+                    }
+                }
+            }
+            overMapDiv = (elem == this.map.div);
+
             elem = elem.parentNode;
         }
         
-        if (inMap) {
-            var delta = 0;
-            if (!e) {
-                e = window.event;
+        // Logic below is the following:
+        //
+        // If we are over a scrollable div or not over the map div:
+        //  * do nothing (let the browser handle scrolling)
+        //
+        //    otherwise 
+        // 
+        //    If we are over the layer div: 
+        //     * zoom/in out
+        //     then
+        //     * kill event (so as not to also scroll the page after zooming)
+        //
+        //       otherwise
+        //
+        //       Kill the event (dont scroll the page if we wheel over the 
+        //        layerswitcher or the pan/zoom control)
+        //
+        if (!overScrollableDiv && overMapDiv) {
+            if (overLayerDiv) {
+                this.wheelZoom(e);
             }
-            if (e.wheelDelta) {
-                delta = e.wheelDelta/120; 
-                if (window.opera && window.opera.version() < 9.2) {
-                    delta = -delta;
-                }
-            } else if (e.detail) {
-                delta = -e.detail / 3;
-            }
-            if (delta) {
-                // add the mouse position to the event because mozilla has a bug
-                // with clientX and clientY (see https://bugzilla.mozilla.org/show_bug.cgi?id=352179)
-                // getLonLatFromViewPortPx(e) returns wrong values
-                if (this.mousePosition) {
-                    e.xy = this.mousePosition;
-                } 
-                if (!e.xy) {
-                    // If the mouse hasn't moved over the map yet, then
-                    // we don't have a mouse position (in FF), so we just
-                    // act as if the mouse was at the center of the map.
-                    // Note that we can tell we are in the map -- and 
-                    // this.map is ensured to be true above.
-                    e.xy = this.map.getPixelFromLonLat(this.map.getCenter());
-                }
-                if (delta < 0) {
-                   this.callback("down", [e, delta]);
-                } else {
-                   this.callback("up", [e, delta]);
-                }
-            }
-            
-            //only wheel the map, not the window
             OpenLayers.Event.stop(e);
         }
     },
 
+    /**
+     * Method: wheelZoom
+     * Given the wheel event, we carry out the appropriate zooming in or out,
+     *     based on the 'wheelDelta' or 'detail' property of the event.
+     * 
+     * Parameters:
+     * e - {Event}
+     */
+    wheelZoom: function(e) {
+        
+        var delta = 0;
+        if (!e) {
+            e = window.event;
+        }
+        if (e.wheelDelta) {
+            delta = e.wheelDelta/120; 
+            if (window.opera && window.opera.version() < 9.2) {
+                delta = -delta;
+            }
+        } else if (e.detail) {
+            delta = -e.detail / 3;
+        }
+        if (delta) {
+            // add the mouse position to the event because mozilla has 
+            // a bug with clientX and clientY (see 
+            // https://bugzilla.mozilla.org/show_bug.cgi?id=352179)
+            // getLonLatFromViewPortPx(e) returns wrong values
+            if (this.mousePosition) {
+                e.xy = this.mousePosition;
+            } 
+            if (!e.xy) {
+                // If the mouse hasn't moved over the map yet, then
+                // we don't have a mouse position (in FF), so we just
+                // act as if the mouse was at the center of the map.
+                // Note that we can tell we are in the map -- and 
+                // this.map is ensured to be true above.
+                e.xy = this.map.getPixelFromLonLat(
+                    this.map.getCenter()
+                );
+            }
+            if (delta < 0) {
+               this.callback("down", [e, delta]);
+            } else {
+               this.callback("up", [e, delta]);
+            }
+        }
+    },
+    
     /**
      * Method: mousemove
      * Update the stored mousePosition on every move.
diff --git a/tests/Handler/test_MouseWheel.html b/tests/Handler/test_MouseWheel.html
index 55110da60d..f5b4933f3a 100644
--- a/tests/Handler/test_MouseWheel.html
+++ b/tests/Handler/test_MouseWheel.html
@@ -57,7 +57,7 @@
         handler.activate();
         var delta = 120;
         if (window.opera && window.opera.version() < 9.2)  delta = -delta;
-        handler.onWheelEvent({'target':map.div, wheelDelta: delta});
+        handler.onWheelEvent({'target':map.layers[0].div, wheelDelta: delta});
         t.ok(pass, "evt.xy was set even without a mouse move");
     }