Installation issue

Am trying to setup a dual-boot Linux system as a precursor to our
development group moving to a similar setup.

System is a Compaq Evo W4000 running Win XP Professional and RH Linux 7.3
using GRUB as the boot loader.

When I go to bring up Linux, it always goes to the shell rather than
graphical login even though I specified Graphical in the setup, and after
running XConfigurator thinking that I might not have specified it properly
in the setup.

If I then try to do an startx, it comes up and gives me the message (foo.edu
is actually our domain of course):
"Could not look up internet address for ergrantham.foo.edu
This will prevent GNOME from operating correctly"

I specified the Medium setting for the firewall, and customized it to allow
DHCP. I'm wondering if something is still getting blocked...

Help will be greatly appreciated!