After upgrading a Red Hat 5.1 system to Red Hat 6.0 using
the upgrade procedure as outlined in the manual,
xterm and xterm-color will not start when chosen from the
gnome menu. They leave a core file after failing to start.
Running the gnome terminal does bring up a window but there
is no shell running in it and the window stays blank.
I found the fix for this problem at
make sure you have the devpts filesystem mounted.