In my case freezes disappeared when I removed the gnome ppa (https://launchpad.net/~gnome3-team/+archive/gnome3).
Having the gnome-ppa installed produced freezes not only in gnome-shell, but also in Unity. -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1184451 Title: Ubuntu 13.10 random screen freeze while Normal OS activites To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1184451/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp