I have upgraded from 13.04 to 13.10 using the system updater an now unity is broken.
It looks like a display problem. The icons and the title bar are all messed up and when I try to open the dash the dash window is unintelligible, looks like a television set on a dead channel.
I have to say that the upgrade failed while trying to copy libwekitgtk. I solved that downloading the library manually and that looks OK now.
I have already tried many apt-get update, upgrades, reinstalling unity and. I always get messages that my system is fully updated. It doesn't look like a missing package problem.
Update: if I try doing
from a shell I get a bunch of these messages:
radeon: The kernel rejected CS, see dmesg for more information
Thanks for the help.