Bug#650930: Not a bug, please close report.

[Alexander Sitnik]

I purged almost all packages from system, every X11 app and Xorg
itself, cleared many config fiels in /etc from my local changes, and
then reinstalled gnome3 again.
This problem has gone. Now I have gnome3 desktop, fully working.
I don't know what caused segfaults, but it's not a Gnome bug, it was
my local problem.
Sorry for bugreport, you may close it.