gnome di kubuntu 12.04

berawal dari gagalnya install KDE di ubuntu,yang selalu meneui kendala error ,,
contoh error :

“Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
kubuntu-desktop : Depends: xorg but it is not going to be installed
E: Unable to correct problems, you have held broken packages.”

lalu saya coba untuk menginstall kubuntu 12.04 terlebih dahulu lalu install gnome,
begini ceritanya :