re: people having graphical issues, unrelated to game/OS install and unrelated to nvidia/ati drivers.

the problem lies in an incompletely understood conflict with realtek onboard audio.

current workarounds include disabling all realtek audio devices through sound preferences and uninstalling all realtek audio drivers.

this requires installation of a third party PCI sound card (or external sound card), e.g. an x-fi card or ht claro family card [as well as drivers] in order to maintain sound output.