If on the kdm login screen the shutdown option
is chosen and either shutdown or shutdown and restart is
selected the screen then flickers between a grey screen
and the login window three times before returning to
the login window which then stays on the screen
until the machine either shuts down or reboots.
No messages about the daemons shutting down appear,
just the kdm login window. Further if the user then
selects shutdown again while the login window
remains present an X error occurs.

In /var/log/messages the following lines appear
on the shutdown options being selected:-

kdm[769]: IO Error in XOpenDisplay
kdm[754]: Display :0 cannot be opened

If I select /sbin/reboot or /sbin/halt while
in a kde session or remote logged in while
kdm is running, the above error does not occur.

In 6.1 this functions correctly.