What are the rules surrounding the BaseMaps and/or Tiled maps in the Flexviewer. When I substitute my base map (spatial ref 4326 like the ESRI maps) and yes its tiled, as the first map and try to use a second map either the Esri imagery or ESRI streets map or whatever, the second map does not display. Do the zoom levels have to match on tiled services? my service has 8 levels where the esri one has 16. There is overlap in the zoom levels. Example below: