I've created a web app which displays sharepoint data on web pages.
This has always worked fine. We upgraded the sharepoint instance to 2010 and all was well within the sharepoint front end.
I open the visual studio web project and change the web reference to point to the new sharepoint address.
I can run the project locally on my workstation (asp.net development server) but when I copy the changes to the web server I get 401 unauthorised access errors.
The IIS settings have not changed.
Windows authentication and impersonation is used (The web.config )
I have rebooted the web server and the sharepoint server on the network admins advice as a server somewhere had been demoted fom being a domain controller and <insert networky speak>