Basemaps generation delay

[JeffreyUtter]

Since including Bing Maps as my second basemap, it take the Bing maps and all others to generate a long time, ie, 12-15 secs for the entire State of Alaska, once I use the slider to see them. If I don't have Bing included, my basemaps generate quickly.
Here is my code.
Anyone know why?
<basemaps>
            <layer label="World Imagery"  type="tiled" visible="true"
                   url="http://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer"/>
          
            <layer label="Aerial" type="bing" visible="false" style="aerial" culture="en-US"/>
           
            <layer label="Detailed Village Aerials" type="dynamic" visible="false" 
             url="http://atlas/ArcGIS/rest/services/AllVillAerials/MapServer" /> 
            <layer label="Streets" type="tiled" visible="false"
                    url="http://server.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer"/>
            <layer label="General Topographical"    type="tiled" visible="false"
                   url="http://server.arcgisonline.com/ArcGIS/rest/services/World_Topo_Map/MapServer"/>
            <layer label="Detailed Topographical" type="tiled" visible="false"
             url="http://server.arcgisonline.com/ArcGIS/rest/services/USA_Topo_Maps/MapServer" />
         <layer label="Shaded Relief" type="tiled" visible="false"
             url="http://server.arcgisonline.com/ArcGIS/rest/services/World_Shaded_Relief/MapServer" />
         <layer label="Ocean Bathymetry" type="tiled" visible="false" 
             url="http://services.arcgisonline.com/ArcGIS/rest/services/Ocean_Basemap/MapServer" />
  
        </basemaps>