I'm trying to get a new Windows Server 2003 box working to host an ASP.NET application that uses Windows Authentication.

Here's some info:

• IIS Anonymous Access is diabled
• IIS Integrated Windows Authentication is enabled
• I've tried it with and without Digest Authentication and it is the same result
• Both my machine and the server are in same active directory domain on the same intranet
• I'm using IE 6

My symptoms:

• In Firefox, via either IP or host name, a login box pops up, and if I enter my NT credentials, it works.
• In IE, via the server IP address, it works perfectly with no login box.
• In IE, via the server host name, it pops up a login box but even if I put in the correct credentials, it just pops up the box again. This is the problem.

Why won't windows auth work in IE via host name but it will via IP address?

Edit:
Here's something else interesting. If I go into my Internet Explorer advanced settings and disable Windows Authentication, it seems to work just fine. And by work I mean that my test .NET app sees my NT ID as the current user.