I just checked out the new ubuntu 11.10 Beta 2 64bit and I can't get my second screen to work.
It worked with kubuntu 11.04 (with binary drivers and with the drivers from nvidia website though not with the latest kernel, but I never checked why it was acting up before) and works with windows.
I installed the nVidia current driver from the 'Additional driver' tool and rebooted which didn't change anything. I then used the nvidia-settings tool and my second screen is marked as 'disabled'. When I enable it as twin-view, the resolution is set automatically but when I hit 'Apply', the following happens.
- The image is mirrored on both screens
- The image is scrambled
- The image is only shown at the bottom lower half of the screen
After some time (I suspect the confirm settings dialog with a time-out) the screen becomes black and only the mouse pointer is shown. It can be moved, but sluggishly. I then have to kill the session from tty.
I installed the drivers from the nvidia website but they did the same thing. (And after 3 tries the system was so mixed up with nouveau and binary drivers that X wouldn't start and I had to restore my system from command line.)