Screen saver login window does not appear.

After looking around, it seems this is the place I need to post my question. Please let me know if this is the right place.  My question is:                   

I type startx to access the GUI on a test system with RHEL 5 which was created with a kickstart file. When the screen protector appears it is missing the log in window. So, I can not log in the system due to the lack of the log in window. I found the package gdm.2.16.0-46.el.x86_64.rpm is related to this log in window. But does somebody know if this is the right one? I have installed around 5 more packages resulting from the packages dependencies. It is still not working. Can someone please point me in the right direction to solve this issue.

Thanks.