This sounds a lot like Bug 67440... what do you think? Is it a duplicate? Also, when my console goes black, I can still run "sudo /etc/init.d/kdm restart" (though I can't see it... be careful to type it correctly!). You?
-- Issuing sudo /etc/init.d/gdm stop causing system to hang https://launchpad.net/bugs/71687 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs