You have some problems with the rom data on your graphics card. Add the line
Option "useROMData " "False"
to the "Device" section on your /etc/X11/xorg.conf . You can edit it typing the command sudo gedit /etc/X11/xorg.conf in the terminal (you'll find that in Applications->Accesories).
The "Device" snippet will look something like that after the edit:
You have some problems with the rom data on your graphics card. Add the line
Option "useROMData " "False"
to the "Device" section on your /etc/X11/xorg.conf . You can edit it typing the command sudo gedit /etc/X11/xorg.conf in the terminal (you'll find that in Applications- >Accesories) .
The "Device" snippet will look something like that after the edit:
Section "Device"
Identifier "Configured Video Device"
Option "useROMData " "False"
EndSection