Windows Server 2003 SP1 IIS6 Trouble with localhost NTLM logons to subwebs

Hi, I just upgraded to SP1. I did standard install and have not installed
the security configuration wizard. I am running IIS6 and I'm hosting 2
sites on the server which are address that are aliased to my servers IP
address. One of the aliases I host under the default website and the other
I host under a second website that is redirected by IIS using the host
header info.

So my server is:
main.company.com
The 1st alias is:
first.company.com
the second alias is:
second.company.com

I have disabled anyomous logons on these sites and I'm using NTLM
authenication. After upgrading to SP1 I can no longer access the websites.
It asks for a username and password but it doesn't accept them. If,
however, I go to http://main/ which is in the local intranet zone I am not
asked for the password and it access the site fine. If I try http://first/
(local intranet) or http://first.company.com (internet) the password box
comes up by it won't accept my password.

My guess is some security setting changed in SP1 that is preventing me from
access this sites from the server.

I would greatly appreciate any and all help on this.

Thanks,
Matt