Silverlight - Accessing Microsoft MapPoint Web Service

I need to access the Microsoft MapPoint Web Service (not the Bing Maps Web Se开发者_开发百科rvice) from a Silverlight application. When I attempt to access the web service, it prompts me for my username / password. I enter my username and password and then a message box pops up that says "not found".

My question is, how do I access the MapPoint Web Service from a Silverlight application?

Thank you!

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AFAIK you should buy subscription in order to access MapPoint services...