I'm an x86-64 Ubuntu 14.04 user with gnome-shell interface.
I left click on the icon of a file or a folder of Nautilus and when I just attempt to drag it, Nautilus immediately closes. This does not happen if I run Nautilus as root.
Other similar problem: having a Terminal window (gnome-terminal) opened, if I left click on any button of upper menu (Files Edit Search Terminal Help...) it closes.
Other: I open gnome-tweak-tool and when I try to change the theme of Window, GTK+, Icons or any other, it closes. Also in this case this does not happen if I run it as root.
I could also verify similar extrange behaviours in other applications.
Any suggestion to solve these problems will be very much appreciated.