Problem with ASP.NET on Win 2k Server

Windows 2k Server running classic ASP apps fine for a few years. Installed .NET Framework. When writing up a simple .aspx page and trying to view it, first I am prompted for a username and password for the website. After entering a username and password with strong permissions, I next go the "Server Application Unavailable" error.

Got past this by creating a custom least privileged ASPNET account for the worker process and editing my machine.config file accordingly (also giving the custom account the proper ntfs permissions and local security permissions). I did this by following the instructions given at http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnnetsec/html/SecNetHT01.asp

Now I am able to see the .aspx page but not before still being prompted for a username and password, and entering a username/password with strong permissions. If I hit 'cancel' on the prompt I get a 401.3 error saying "Access denied by ACL on resource IIS".

It seems to me that there are still some ACL's that need my custom ASPNET account. Here's a list of folders I've given the custom ASPNET account access to...

WINNT\Microsoft.NET...\<version>\Temporary ASP.NET Files (Full Control)

WINNT\temp (Read/Write/Delete)

WINNT\assembly (Read)

c:\inetpub propagated all the way down, of course including the folder I have the .aspx file in. (Read)

WINNT\Microsoft.NET, propagated all the way down (Read)

WINNT\system32 (Read)