I'm running Ubuntu 12.04.3 on a Toshiba Satellite L745. I've been doing this happily for two years now but sporadically have Nvidia-related problems following Ubuntu updates. 24 hours ago I accepted all available updates and now I cannot boot.
I have fixed this problem before using advice on ask ubuntu pages such as: Can I install extra drivers via the command prompt?
However, this time the computer will not respond to jockey-text commands (dbus.exceptions) and tells me Nvidia current is already installed. I am unable to boot Ubuntu after a couple of hours of trying and am getting frustrated. Reboot attempts confirm the problem is nvidia based: "the nvidia kernel module has 310.44 but this nvidia driver component has 304.88"