I looked in the physX_open function a bit more in it but could not find anything that explains this weird behaviour. Anyway I did find an other semi solution; setting sc_screen_default.settings.lights.sunShadows = 0; also removes the black lines and does not give any errors (plus it actually increases fps alot so the game is than also playable on older / slower systems, which is probably on the same computers that play the game on lower resolutions than their monitor/system can handle).