When I tried installing Ubuntu/Kubuntu, it used to always fail to even boot the live cd. Tried changing the display to D-Sub instead of HDMI, tried removing a suspect HDD, to no avail. Finally changed the grub settings of the live cd to remove acpi et al. And it booted. Installation proceeded fine, but the first boot after install again failed. Tried to get to recovery, and it started X normally! Finally, I installed the Additional Nvidia drivers, and now X boots fine. I still get segmentation fault errors for the Window manager.