Open GL must be enabled.for that check /etc/X11/xorg.conf
section "Module".check urs with below:
Code:
Section "Module"
Load "bitmap"
Load "dbe"
Load "dri"
Load "ddc"
Load "extmod"
Load "freetype"
Load "glx"
Load "int10"
Load "vbe"
EndSection
so dri must be enabled too.check in synaptic for libgl1-mesa-dri whether installed if not install.edit xorg.conf Modules section to look as above