https://bugzilla.redhat.com/show_bug.cgi?id=966799
--- Comment #3 from Adam Williamson awilliam@redhat.com --- I note that the F19 MATE spin's Keyboard Preferences dialog has a 'Keyboard model' setting. By default it shows as "Unknown" and appears to actually be pc104: it acts as the OP describes GNOME acting, if you add the UK layout, the LSGT key is missing. But if you change "Keyboard model:" to "Generic 105-key (Intl) PC", the LSGT key does indeed show up in the UK layout. That rather indicates that, indeed, the problem is that _something_ in the stack is setting the default model to pc104 (and GNOME doesn't have any option to change this, so you can't recover).