Comment 276 for bug 1268257

With the most recent kernel update the reconfigure trick has stopped working for me. I just moved to the xorg-edgers ppa to fix the problem. Found some instructions people can follow.

http://ubuntuguide.net/install-nvidia-proprietary-drivers-in-ubuntu-14-04

You should be safe going to 340 but you can check:

http://www.nvidia.com/object/unix.html

and go to 340 for your arch (x86 or x86_64) and click on supported products. Look for your card. If it isn't supported go down a legacy version and check the next one. Edgers has support for back to 304.