I have an nVidia GTX 570 card in my machine, with two monitors connected. This very, very nearly works. I am running Kubuntu 12.10. Upon installation, both monitors worked great, I only had to swap their order (my primary is on the right, it assumed left) and I was able to do so with the Ubuntu display manager app.
Then I enabled the nVidia drivers. They worked right off the bat! Except, they also presumed the wrong physical order of my displays. So, I went into the nVidia settings app to change that. Things went downhill fast. Now, even with the nVidia drivers after reboot, both monitors were working correctly in every way except for their order. And in the nVidia settings app, under the GPU 0 item it recognizes both monitors, and it recognizes their proper native resolution (1920x1200 for one, 1680x1050 for the other). However, when I go to the X Server Display Configuration item, it displays both monitors with a resolution of 1024x768 embedded within their proper size. I can only select 1024x768 as the max resolution of either monitor here. I can drag their boxes around and set them up properly physically, but if I apply these settings, even with Auto selected for their resolutions, it changes both monitors to 1024x768.
My best guess as to why this is is because the 1920x1200 monitor runs at 75Hz while the 1680x1050 monitor runs at 60Hz, though it can do 75Hz at lower resolutions. I can only guess that 1024x768 is the highest resolution that allows them both to run at the same refresh rate (though the 1920x1200 can easily run at 60Hz as well, and it appears to be doing so right now).
I have been trying to research this problem, but I haven't found anyone with this problem where the nvidia settings app clearly recognizes both monitors perfectly well, it simply refuses to allow setting the resolutions it is already running the monitors at. I am willing to craft a custom xorg.conf if I have to, but I find some instructions recommending turning on Xinerama, others advocating TwinView, and none adequately explaining the purpose of various lines (for instance I do not know if I should use a 'metamode' or how to create one if necessary).
Any help would be greatly appreciated. I just want the nvidia driver to do what it is doing right now (though bumping my larger monitor to its native 75Hz wouldn't be bad) except let me move the mouse from one screen to the other without having to wrap around the opposite way of how the monitors are laid out!