There are some issues between Ubuntu 12.04 system with Intel NM70 chipset.
Please make sure to update to latest Kernal core or add the patch for on-board graphic.
Try to add "i915.i915_enable_rc6=0" to /etc/default/grub "GRUB_CMDLINE_LINUX_DEFAULT". Should look something like this then:
Code:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash i915.i915_enable_rc6=0"
Then run:
Code:
sudo update-grub
And reboot.
