gnome-session problem with FC2

This morning I woke up to find my Fedora (core 2) box had stopped (due
to the electricity supply twitching). When I re-started it, I
attempted to log in only to find an error being reported when logging
in as a user:

/etc/X11/gdm/PreSession/Default: Registering your session with wtmp
and utmp
/etc/X11/gdm/PreSession/Default: running: /usr/bin/X11/sessreg -a -w
/var/log/wtmp -u /var/run/utmp -x "/var/gdm/:0.Xservers" -h "" -l ":0"
"chris"
/home/chris/.XClients-default: line 2: exec: gnome-session: not found

When logging in as root, I get only a graphical command box.

Can anyone here cast any light on this problem and how I can correct
it?

Thanks
Chris Jones