Say hypothetically you're working on an application that will consume a MapPoint WebService using some flavour of Visual Studio 2005 Beta 2.  And further suppose that the MapPoint Web Service, after being added as a Web Reference to your project, is giving you the following grief when you call the service:

Server did not recognize the value of HTTP Header SOAPAction:­-30/FindAddress.

Then the advice you need so that you can keep slugging ahead is here, in Andrew Coates' article.  You need to work around some strange behavior in the WSDL generator in the Beta of Visual Studio 2005.

[Update: this workaround is a little more frustrating when working from ASP.NET 2.  Because you don't have access to Reference.cs from ASP.NET 2 (it is automagically created for you instead), you can't make the tweaks Andrew suggests.  I ended up (1) generating the web service's Reference.cs using WinForms 2, (2) tweaking it as per Andrew's suggestions, (3) moving Reference.cs from WinForms into ASP.NET into App_Code as MapPointServiceReference.cs, (4) hacking in the URLs for the secure MapPoint web services at the top of said file manually.  I've posted the resulting file at the link above.  Note to most excellent Visual Studio dudes: please make this work properly in the final release; that would be most triumphant... :) ]