Comment 3 for bug 11334

Since gnome desktop that firefox attempts to blend with on linux uses the
freedesktop specs for clipboard management, anything copied from firefox is lost
when firefox is closed as firefox does not follow these specifications:
http://www.freedesktop.org/wiki/Standards_2fclipboards_2dspec

in other applications copying something and closing the application does not
cause the copied content to be lost (this clipboard manager was implemented in
gnome 2.12)