I've got Windows Server 2k3 with IIS6 hosting a couple ASP.NET MVC 2 applications (.NET 4), all in the Default Web Site. Most of them simply use Integrated authentication, but a couple use forms as well. All the applications work properly and are correctly accessible.

The problem I'm trying to resolve is access to the default document. It is currently specified as index.htm. Both index.htm and the Default Web Site are configured to allow anonymous access (with none of the authenticated acces boxes checked). However, access is denied to the file.

Accessing via server.domain.tld/ and server.domain.tld/index.htm both yield 401 errors. However, server.domain.tld/default.htm (file does not exist) properly returns a 404.

If I alter the file security on index.htm to allow integrated authentication, then requesting /index.htm directly works properly for users with domain accounts, but anonymous users get a login prompt/401.

How can I configure IIS to allow all users to view index.htm via server.domain.tld/?