Segmentation fault using xvfb-run under debian

[Lootek]

I've got the same problem, but after few weeks finally dealed with it
- so this is what I've done (I don't get why the error is, so some of
the steps may be unnecessary):
first run Xvfb manually from the shell, setting display number (10 in
the example) and other few options (-extension GLX deals with some
errors you are likely to get next):
$ Xvfb :10 -auth /tmp/xvfb-auth -ac -extension GLX -screen 0 1024x768x24

Next, edit /etc/apache2/envvars (or similar) by adding these 4 lines
(put your xulrunner libs path):
export DISPLAY=:10
export XAUTHORITY=/tmp/xvfb-auth
export MOZILLA_FIVE_HOME=/usr/lib/xulrunner-1.9.1
export HOME=/tmp/
Restart apache. This is needed because scripts run by/from apache have
different environment variables set (this is why we got "no display
found" message).

Now it should work :) (the error about "RANDR extension" i apache logs
is nothing important)

If something is still wrong, try updating python-gtkmozembed and
xulrunner (and be careful about dependencies bug - this python package
may not require newer xulrunner during install - but it DOES require
it!)
In my case:

$ sudo dpkg -l | grep python-gtkmoz
ii  python-gtkmozembed                       2.25.3-6
 Python bindings for the GtkMozEmbed Gecko library

$ sudo dpkg -l | grep xulrunner
rc  xulrunner-1.9                            1.9.0.19-7
 XUL + XPCOM application runner
ii  xulrunner-1.9.1                          1.9.1.16-4
 XUL + XPCOM application runner

Hope this helps :)