Whenever I move/copy/rename a file using Nautilus, or download a file using Firefox, Gnome-Shell freezes for about 5 to 10 seconds. Only the mouse is still responsive, but I can't click or manipulate anything. This is immensely frustrating. I'm seeing no explicit error messages. I'm using Ubuntu 12.10. Is there anything I can do to fix this?
what you can do is try to reload gnome by running the following command on your shell
DISPLAY=:0 gnome-shell --replace
once you run this command you press control-alt f7 and you gnome will be up and running again :)