Thanks for the reply. I did the mapsource update that you recommended. This helped a lot. The USGS map are working much better now. However, even so there are random tiles that still get the red X.
I am mostly interested in coverage for the SW of US but also Europe and Central America.
OpenStreetMap CloudMade Default Style - fails to load for any zoom level.
OpenStreetMap Hikebikemap.de - Previews down to about zoom 13 then failing randomly or completely at higher zoom levels.
OpenStreetMap 4UMaps.eu - Seems to work ok except only detail to zoom level 15
USGS National Map Satellite+ - Does not work at all (All X)
USGS National Map Vector - Does not work at all (All X)
Are there other/better topographical/terrain map sources available?