3.7 problem: replacing xdm with kdm

[Dave Feustel <dfeustel_(_at_)_verizon_(_dot_)_net>]

I am now running 3.7. I got graphical logins via xdm working and
decided to replace xdm with kdm. I changed the call of xdm
in rc to a call to kdm and rebooted. kdm comes up and accepts
input, but I cannot log in with any id, including root. (I always get 
the  message 'login failed'.) Are there additional changes that I 
need  to make to use kdm instead of xdm? 

Thanks,
Dave Feustel