Wait for the page to finish loading before trying to add any data

object to the map as IE won't be ready to draw vectors until the
page is fully loaded. Closes #2692.

app/views/site/index.html.erb

@@ -170,7 +170,8 @@ end
         url += "/full";
       <% end %>
 
-      addObjectToMap(url, <%= object_zoom %>);
+      // IE requires Vector layers be initialised on page load, and not under deferred script conditions
+      Event.observe(window, 'load', function() { addObjectToMap(url, <%= object_zoom %>) });
     <% end %>
 
     map.events.register("moveend", map, updateLocation);