I have been playing around trying to use a wcf service with a vb silverlight 2 beta 2 app and kept getting a InvalidOperationException when trying to call the wcf service (of course it works fine in c#).
Tim Anderson's blog correctly shows all you have to do is give the contract a fully qualified namespace to fix the issue.
http://www.itwriting.com/blog/?p=666
So in a nut shell vb generates this in ServiceReferences.ClientConfig
<client> <endpoint address="http://localhost:1735/Service1.svc" binding="basicHttpBinding" bindingConfiguration="BasicHttpBinding_IService11" contract="ServiceReference1.IService1" name="BasicHttpBinding_IService1" />
</client>
When it should be
<client> <endpoint address="http://localhost:1735/Service1.svc" binding="basicHttpBinding" bindingConfiguration="BasicHttpBinding_IService11" contract="VBSqlData.ServiceReference1.IService1" name="BasicHttpBinding_IService1" /> </client>