SL6: how to default to KDE?

[Jeff Siddall]

I have ~/.Xclient set to start KDE (courtesy of the old switchdesk 
script from EL5 which seems to be missing in EL6) and 
/etc/sysconfig/desktop contains DESKTOP="KDE" and DISPLAYMANAGER="KDM" 
and yet still GDM continues to run and login to Gnome by default.

What do I have to do to get KDE?
Thanks,

Jeff