It appears that the kdm mem corruption problem is not gone. It still comes up, but is no longer causing an issue. But did solve the lock-up as being a swap issue with Kubuntu. Xorg and KDM were simply the symptom.
-- KDM detected memory corruption https://launchpad.net/bugs/47455 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
