Comment 15 for bug 1362848

After some time and prayer I've somehow got it fixed. :) Just totally reinstalled drivers.
Before I tried a lot of different stuff - like installing bumblebee, gdm or different drivers for example. That's why not all of this steps will be required for You I believe. On the other hand maybe I did something more before, which You will not find here. Anyway You can try it.

sudo ppa-purge ppa:bumblebee/stable
sudo rm /etc/X11/xorg.conf*
sudo apt-get purge nvidia* bumblebee*
sudo rm /etc/X11/xorg.conf
sudo apt-get autoremove
sudo apt-get update
sudo apt-get upgrade
sudo reboot
sudo apt-get install nvidia-331 nvidia-prime
sudo reboot

And before I purged 'xorg-edgers' ppa with 'ppa-purge ppa:xorg-edgers '.

And my current '/etc/X11/xorg.conf' content:
"

Section "ServerLayout"
    Identifier "layout"
    Screen 0 "nvidia"
    Inactive "intel"
EndSection

Section "Device"
    Identifier "intel"
    Driver "intel"
    BusID "PCI:0@0:2:0"
    Option "AccelMethod" "SNA"
EndSection

Section "Screen"
    Identifier "intel"
    Device "intel"
EndSection

Section "Device"
    Identifier "nvidia"
    Driver "nvidia"
    BusID "PCI:1@0:0:0"
    Option "ConstrainCursor" "off"
EndSection

Section "Screen"
    Identifier "nvidia"
    Device "nvidia"
    Option "AllowEmptyInitialConfiguration" "on"
    Option "IgnoreDisplayDevices" "CRT"
EndSection

".

Hope that it will also work for You.