Server running Microsoft CRM cannot connect, but every other machine on network can

I have an annoying problem.

On every machine on the network, browsing to our internal MS CRM URL works fine. However, if I log into the actual server itself and try to connect the same credentials just do not work. I get this error:

HTTP Error 401.1 - Unauthorized You do not have permission to view this directory or page using the credentials that you supplied.

I can't figure it out. They're on the same domain, everything should be fine. It's a big problem because there is an application running on the server that needs to connect to the CRM webservice - and fails.

Even with Basic Auth, I enter the username and password and it fails.

Any ideas?

From stackoverflow

• You might be hitting the loopback security check. Read this KB article to see if you are, and how to disable it so things will work: http://support.microsoft.com/default.aspx?scid=kb;en-us;896861