For God's sake, people, these grey-outs seem to be a Gnome feature. However,
they do not happen in CentOS's Gnome.
Under Ubuntu I recommend XFCE or LXDE or even FVWM-crystal (Which I do not
use, it is not suitable for my mother). I warmly recommend XFCE4 or
Xubuntu-Desktop. Fast, efficient, no grey-outs. I will try Compiz again on XFCE
(Yes, it works, but there is the risk of screwing up the GUI and then you have
to repair it).

So, no more Gnome on Ubunut for everyday work...

Now, I am writing under Aptosid.