Seems you've been quite unlucky! :)
The [segfault] is caused by your video driver. Somehow it does not fully support 3D OpenGL; most likely you are using a MESA driver. Try to upgrade to the latest vendor drivers, that should solve the issue.
I'm afraid we've been hit by this issue as well, using ATK-10.8.2 on Redhat/CentOS-5.5, and displaying on Macs which run the latest Xquartz-2.5.3 (http://xquartz.macosforge.org/trac/wiki) X11 server on Mac OS X-10.6.5. /opt/X11/bin/glxgears works, and we have:
$ xdpyinfo | grep GL
GLX
SGI-GLX
vnl used to work prior to Mac OS 10.6.5 (which was released 2010-11-18). /opt/X11/lib is all-new in this release, dated 2010-08-15;
Regards, Michael