It looks to me like either you don't have direct rendering on, or the OpenGL libs aren't propererly installed.
Does ebunty have eselect? Try eselect nvidia. Or something, I forget the exact syntax. What does glxinfo say?
EDIT: I forgot, to make sure the Opengl libs are installed, try switching into xorg-x11 mode by typing eselect xorg-x11 (or x11-xorg? I'm on windows at work now and can't check). Again, i forget the exact syntax for eselect. Then switch back into nvidia mode to turn on direct rendering.