401.2 error processing

I have an intranet app that uses Windows Integrated
authentication. Users that dial-in are not authenticated
successfully, and IIS throws a 401.2
I thought the solution might be as follows:
At the root (which is NOT under NT Integrated
authentication), I would put a custom error page that
fires on the 401.2, displays a nice message, and redirects
the user to a generic asp.
The problem is that the custom error page comes up
correctly, but IIS continues to challenge the user with
the dialog to input their user name/pw/domain.

\ web site root folder (Anonymous)
401_2.htm
\Authenticate folder (Integrated Security)

What are the NTFS permissions on 401_2.htm? IUSR_...
and/or IWAM_... needs at least read access.

 >-----Original Message-----
 >I have an intranet app that uses Windows Integrated
 >authentication. Users that dial-in are not authenticated
 >successfully, and IIS throws a 401.2
 >I thought the solution might be as follows:
 >At the root (which is NOT under NT Integrated
 >authentication), I would put a custom error page that
 >fires on the 401.2, displays a nice message, and
redirects
 >the user to a generic asp.
 >The problem is that the custom error page comes up
 >correctly, but IIS continues to challenge the user with
 >the dialog to input their user name/pw/domain.
 >
 >\ web site root folder (Anonymous)
 >401_2.htm
 > \Authenticate folder (Integrated Security)
 >.
 ><!-- ~MESSAGE_AFTER~ -->