I recently installed Ubuntu 12.04 on my desktop. I have three monitors, and after installing, ubuntu only detected one at 1080p. I downloaded the driver from the nvidia website, but when I stop lightdm and try to run the driver, it gives me an error message:

ERROR: Unable to find the kernel source tree for the currently running kernel. Please make sure you have installed the kernel source files for your kernel and that they are properly configured; on Red Hat Linux systems, for example, be sure you have the 'kernel-source' or 'kernel-devel' RPM installed. If you know the correct kernel source files are installed, you may specify the kernel source path with the '--kernel-source-path' command line option.

I tried instead to install the driver via the terminal, with the X ppa. The installation seemed to work, but when I rebooted, my display was at 640x480 resolution, with no other options for resolution. The NVIDIA X Server settings program is there now, but when I run it, it simply tells me that I don't seem to be using their driver, and that I should run nvidia-xconfig as root. Doing so doesn't help, I simply get the same issue again. I checked the file at /etc/X11/xorg.conf, and it's an NVIDIA file (has nvidia in the header).

Does anyone know something else I can try?

EDIT: Forgot to mention, I tried installing drivers via the "Additional Drivers" GUI utility, there were two options, one of them marked "(post-release updates)". I tried both of them, in both cases it tried to download and install for a while, then said that there was an error, and that a description could be found at /var/log/jockey.log. Both logs were over 700 lines