We've had a number of problems related to browsers complaining on this line.

The popups go away, then cause:
[Exception... "Node was not found" code: "8" nsresult: "0x80530008 (NS_ERROR_DOM_NOT_FOUND_ERR)" location: "/lib/OpenLayers.js Line: 7663"]
This will hopefully silence the exception. 


git-svn-id: http://svn.openlayers.org/trunk/openlayers@1499 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Map.js

@@ -438,7 +438,9 @@ OpenLayers.Map.prototype = {
     removePopup: function(popup) {
         this.popups.remove(popup);
         if (popup.div) {
-            this.layerContainerDiv.removeChild(popup.div);
+            try { this.layerContainerDiv.removeChild(popup.div); }
+            catch { } // Popups sometimes apparently get disconnected
+                      // from the layerContainerDiv, and cause complaints.
         }
         popup.map = null;
     },