XDMCP no Kubuntu 8.10

Edite o arquivo:
sudo vi /etc/kde4/kdm/kdmrc

Altere a linha:
[Xdmcp]
# Whether KDM should listen to incoming XDMCP requests.
# Default is true
Enable=false
Para:
[Xdmcp]
# Whether KDM should listen to incoming XDMCP requests.
# Default is true
Enable=true

[# XDMCP access control file in the usual XDM-Xaccess format.
# Default is "/etc/kde4/kdm/Xaccess"
#Xaccess=
Para
# XDMCP access control file in the usual XDM-Xaccess format.
# Default is "/etc/kde4/kdm/Xaccess"
Xaccess=/etc/kde4/kdm/Xaccess

Edite o arquivo:
sudo vi /etc/kde4/kdm/Xaccess

Altere a linha:
#* #any host can get a login window
Para todos:
* #any host can get a login window
Ou somente para alguns:
192.168.1.153 #any host can get a login window

Portas no Firewall:
iptables -I INPUT -p udp --sport 177 -j ACCEPT
iptables -I INPUT -p tcp --dport 6000 -j ACCEPT