Solved following the indications of http://www.ubuntugeek.com/howto-install-nvidia-drivers-manually-on-ubuntu-10-04-lucid-lynx.html and installing driver version 256.53
Solved following the indications of http:// www.ubuntugeek. com/howto- install- nvidia- drivers- manually- on-ubuntu- 10-04-lucid- lynx.html and installing driver version 256.53