I have got the same problem and now it was solved by just remove xorg-driver-fglrx
sudo apt-get remove xorg-driver-fglrx sudo reboot
Then all my OpenGL and blank screen bug disappear.
I have got the same problem
and now it was solved by just remove xorg-driver-fglrx
sudo apt-get remove xorg-driver-fglrx
sudo reboot
Then all my OpenGL and blank screen bug disappear.