I have 12.04 running on Intel dual core with Nvidia 8400 GS. I had installed the post-relase updates for Nvidia, but encountered some problems, so removed [deactivated] them through "Aditional drivers".
After restarting, when I went to install the recommended version current drivers through "Additional drivers", I get the following error:
Sorry, installation of this driver failed. Please have a look at the log file for details: /var/log/jockey.log