Re: 100.14.11 and geforce 7025
Contrary to your assertion, X is running in Twinview, so that is clearly not the problem. I'm not sure what you mean by a "7025 driver" as you should be using the same 100.14.11 driver for both of the GPUs that you're using.
Just because something doesn't work as expected does not mean that it is a driver bug. You've not provided any information as to why you feel that this is a driver bug rather than a hardware problem.