LightDM on Xubuntu 11.10 horror story

I have installed xubuntu 11.10 on one machine that was already with kubuntu installed on it
after reboot there was nologin only some flashes
I have disabled graphical boot , deleted quiet and all the pretty options in the grub menu (nomodeset added too)
no luck
removed kdm still no luck
I have launched lightdm manually with debug flag
lightdm -d and saw that it needs unity-greeter and there was no such thing as unity-greeter installed
so i have installed it  and changed to the classic gtk greeter
In /etc/lightdm/lightdm.conf i have changed
greeter-session=lightdm-gtk-greeter

Reboot and still in the logs i saw "lightdm main process  TERM signal"
and No greeter .
What is weird that lxdm started if launched from command line also
the start-xfce4 worked ok
what to do ?
i have added in rc.local
start lightdm and after reboot
the login was ok again