If you got hit by the KDE 4.11 problem you'll probably have to revert to vanilla kubuntu (KDE 4.10). However, purging the kubuntu beta ppa packages (
) does not work 100% straight with ppa-purge (it leaves you with unresolved dependencies and thus you cannot install KDE 4.10). After ppa-purge I had to do
in order to identify all the kubuntu ppa packages and delete all of them before installing KDE 4.10. It's easy but takes some time. If you have to do this, ensure that you have a working network connection before doing the ppa-purge.
dpkg -l | grep 13.04 | grep ppa