I did not have the commented line, so I added it to the section [X-:*-Core]. It worked! Thanks a lot, franceloc.
-- Lockup problems with both the free xorg ATI driver and the proprietary fglrx driver, using various ATI cards https://launchpad.net/bugs/30447 -- kubuntu-bugs mailing list kubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/kubuntu-bugs