Comment 51 for bug 71593

To fix this problem, u have to install mgltools-opengltk too.

Like this:
$ sudo apt-get install python-opengl python-gtkglext1 mgltools-opengltk

Source in brazilian portuguese:
http://gdpufes.blogspot.com/2009/06/linux-habilitar-o-xadrez-do-ubuntu-em.html