[SOLVED] Fedora17 Gnome4 desktop loading instead of xfce. Stable system before today

Problem:

On reboot Fedora 17 boots into Gnome4 desktop instead of Xfce

Fedora 17 Xfce Spin installed from bootable stick last september. System has been stable up until yesterday afternoon.
Performed reboot and system came up with gnome4 basic desktop instead of my xfce desktop.

Single user with admin privliges
Release 3.8 (forget rest of string)
Grub2 loader
No other operating systems installed

Just prior to problem system-config-network was installed using
$ sudo yum install system-config-network
application opened ok after install
performed several network changes
rebooted
Problem appears, Assumed as a result of latest install
rebooted into "recovery mode"
as root removed system-config-network using yum
# yum remove system-config-network
Rebooted No change in problem

Questions

How do I recover my system as to start in xfce desktop as configured rather than gnome4

Currently online via gnome4. Have original liveUsb used for original install


Thanks in advance for your advice
David