i have been having a Serious Issue with my LG notebook and its Nvidia Geforce 310M GPU. It usualy (99% of the time) happens when i leave the computer idle for a while, but it has also happened sometimes while i was using the PC. Suddenly, (usualy when computer is idle) the screen goes black, and the pc freezes completely on the black screen. (not even ping responses). The only sollution is to Hard Reset the machine. When analizing the syslog, i see the following error:

Sep 18 20:58:08 yuri-notebook kernel: [ 1936.510073] NVRM: GPU at 0000:01:00.0 has fallen off the bus.
Sep 18 20:58:08 yuri-notebook kernel: [ 1936.510087] NVRM: GPU at 0000:01:00.0 has fallen off the bus.
Sep 18 20:58:08 yuri-notebook kernel: [ 1936.510157] delay: estimated 354, actual 1
Sep 18 20:58:08 yuri-notebook kernel: [ 1936.510173] delay: estimated 353, actual 0

I have already tryed different versions of the Nvidia Drivers, and also tryed removing each of my 2 DDR3 memories. The problem does not seem to be hardware, because when i boot into windows 7, it works normaly, for days.

I am desperate with this problem, because it makes my Ubuntu practicaly unusable.

Thanks in advance,

Yuri