Are you talking about the error happening in "antOons 3D Studio"? This is happening because the Nivdia rpm seems to have a packaging bug (it expects an xorg.conf which isn't there at install time.
You could try building the image without the Nivdia package until we have a work around.
One possible hack would be to include those rpms (as overlay files) and install them at boot time.
... will look into this.
It is not working for me still getting rpm error when trying to build.