Certain Users getting double logon screen when accessing the Portal

Question

I have about 15 users out of 2500 that are getting the double logon screen when accessing the Portal. It's very intermittent, one minute it works fine the next minute it doesn't. I've tried almost everything on the client side, opened a case with Microsoft. Still no help.
Does anyone have any ideas on this?

Answer 1

The users are getting a login page with 2 login boxes. they can login, but it does not single sign them in.
Yes we are using SPNEGO, and it works for everyone except these users, and it does work sometimes for them
Yes it is possible these users are using NTLM becasue I see some events in the event viewer on the client indicating this
You find an event similar to the following event in the system event log:
Event Type: Warning
Event Source: LSASRV
Event Category: SPNEGO (Negotiator)
Event ID: 40961
Date: 10/27/2004
Time: 1:00:50 PM
User: N/A
Computer: COMPUTER
Description: The Security System could not establish a secured connection with the server ldap/DC01.corp.com/[email protected] No authentication protocol was available.
Edited by: Jeremy Rafuse on Dec 21, 2007 7:26 PM