What is the make/model of your laptop? What is the video hardware?
Linux installation tip #1
This is why after doing installs you should choose to boot runlevel 3 and not 5 until you make sure X works correctly.
You need to boot runlevel 3 and either run:
Just hand edit /etc/XF86Config, which you might end up doing anyway. redhat-xfree86-config is a new tool and a work in progress.