Have you tried manually insert the user on "Manual Input of User Names" box ?
I've had a similar problem in one of my clients and insert the users manually solved my problem.
In my case, I believe it's a Qlikview bug, as informed in the following post
http://community.qlik.com/message/211149#211149, because I had to insert all users manually.
Hope this helps you.
Yes. customer actually has two servers. I did exactly same thing on these two servers. One works, user can be immediately found after I added it into the new server's active directory. The other one does not. User cannot be found after I added it into the old server's local users and groups.
Customer is ok because they are shutting down the old server. I just want to find out why this happened.
Thank you anyway.