diff --git a/lib/OpenLayers/Map.js b/lib/OpenLayers/Map.js
index 6e2dbf809b..2ca3dec334 100644
--- a/lib/OpenLayers/Map.js
+++ b/lib/OpenLayers/Map.js
@@ -77,6 +77,18 @@ OpenLayers.Map.prototype = {
     /** @type int */
     zoom: 0,    
 
+    /** Used to store a unique identifier that changes when the map view 
+     * changes. viewRequestID should be used when adding data asynchronously 
+     * to the map: viewRequestID is incremented when you initiate your 
+     * request (right now during changing of baselayers and changing of zooms). 
+     * It is stored here in the map and also in the data that will be coming 
+     * back asynchronously. Before displaying this data on request completion, 
+     * we check that the viewRequestID of the data is still the same as that 
+     * of the map. Fix for #480
+     * 
+     * @type String */
+    viewRequestID: 0,
+
   // Options
 
     /** @type OpenLayers.Size */
@@ -448,6 +460,11 @@ OpenLayers.Map.prototype = {
 
                 // set new baselayer and make it visible
                 this.baseLayer = newBaseLayer;
+                
+                // Increment viewRequestID since the baseLayer is 
+                // changing. This is used by tiles to check if they should 
+                // draw themselves.
+                this.viewRequestID++;
                 this.baseLayer.setVisibility(true, noEvent);
 
                 //redraw all layers
@@ -743,6 +760,9 @@ OpenLayers.Map.prototype = {
                 for (var i = 0; i < this.popups.length; i++) {
                     this.popups[i].updatePosition();
                 }
+
+                // zoom level has changed, increment viewRequestID.
+                this.viewRequestID++;
             }    
             
             var bounds = this.getExtent();
diff --git a/lib/OpenLayers/Tile/Image.js b/lib/OpenLayers/Tile/Image.js
index 6539e933ed..1ba3c94b88 100644
--- a/lib/OpenLayers/Tile/Image.js
+++ b/lib/OpenLayers/Tile/Image.js
@@ -34,6 +34,7 @@ OpenLayers.Tile.Image.prototype =
     destroy: function() {
         if ((this.imgDiv != null) && (this.imgDiv.parentNode == this.layer.div)) {
             this.layer.div.removeChild(this.imgDiv);
+            this.imgDiv.map = null;
         }
         this.imgDiv = null;
         OpenLayers.Tile.prototype.destroy.apply(this, arguments);
@@ -52,6 +53,8 @@ OpenLayers.Tile.Image.prototype =
         if (this.imgDiv == null) {
             this.initImgDiv();
         }
+
+        this.imgDiv.viewRequestID = this.layer.map.viewRequestID;
         
         this.url = this.layer.getURL(this.bounds);
   
@@ -132,6 +135,10 @@ OpenLayers.Tile.Image.prototype =
                                              null, null, null, 
                                              this.layer.opacity);
         }
+
+        // we need this reference to check back the viewRequestID
+        this.imgDiv.map = this.layer.map;
+
     },
 
     /**
diff --git a/lib/OpenLayers/Util.js b/lib/OpenLayers/Util.js
index c275564dce..edf3522595 100644
--- a/lib/OpenLayers/Util.js
+++ b/lib/OpenLayers/Util.js
@@ -217,8 +217,25 @@ OpenLayers.Util.setOpacity = function(element, opacity) {
 }
 
 OpenLayers.Util.onImageLoad = function() {
-    this.style.backgroundColor = null;
-    this.style.display = "";  
+    // The complex check here is to solve issues described in #480.
+    // Every time a map view changes, it increments the 'viewRequestID' 
+    // property. As the requests for the images for the new map view are sent
+    // out, they are tagged with this unique viewRequestID. 
+    // 
+    // If an image has no viewRequestID property set, we display it regardless, 
+    // but if it does have a viewRequestID property, we check that it matches 
+    // the viewRequestID set on the map.
+    // 
+    // If the viewRequestID on the map has changed, that means that the user
+    // has changed the map view since this specific request was sent out, and
+    // therefore this tile does not need to be displayed (so we do not execute
+    // this code that turns its display on).
+    //
+    if (!this.viewRequestID ||
+        (this.viewRequestID == this.map.viewRequestID)) { 
+        this.style.backgroundColor = null;
+        this.style.display = "";  
+    }
 };
 
 OpenLayers.Util.onImageLoadErrorColor = "pink";
diff --git a/tests/grid_inittiles.html b/tests/grid_inittiles.html
index 78905d621d..da665d55fc 100644
--- a/tests/grid_inittiles.html
+++ b/tests/grid_inittiles.html
@@ -11,7 +11,7 @@
     <script type="text/javascript">
         <!--
         function init(){
-            map = new OpenLayers.Map('map', {'maxResolution': 1.40625/2, tileSize: new OpenLayers.Size(256,256)});
+            var map = new OpenLayers.Map('map', {'maxResolution': 1.40625/2, tileSize: new OpenLayers.Size(256,256)});
             ww = new OpenLayers.Layer.WMS( "Basic", 
             "http://labs.metacarta.com/wms-c/Basic.py?", 
             {layers:"basic"});