xorg-x11-server crashes during installation of RHEL 6.4

Issue

• When booting from the RHEL 6.4 install disc, X startup fails and fails back to the text mode installer

• I'm booting up my server to install 6.4 and after the prompt about testing the media, I get the following message flashed at the bottom of the screen:

X startup failed, falling back to text mode

then it continues in text mode. But when I boot up with 6.3, I don't get this message and the install continues normally in graphical mode. Why is this happening with 6.4?