I have been having a strange issue. When running my Silverlight app from a server the map underlay does not show. I get all the points just fine, but I don't see the geographical map. When running from my localhost dev environment everything is working fine. I have run fiddler against the app and when it tries to go to dev.virtualearth.net ( I assume this is the geographical map service call) I get a 307 return result, and following message. "Redirect (authentication_redirect_to_virtual_host) You are being redirected to the authentication virtual host." I am using the Bing map setting and I have a Bing map key. I should also state that is only happens with IE, all other browsers work just fine.

Any idea what would cause this? 

Hello Richard,

It looks like a problem with the proxy server. I've searched in Internet and found that similar problem can occur when a blue coat proxy server is used. In this case it requires the network team to create a rule to allow traffic from the webserver to the web service/REST.

Best wishes,
the Telerik team