Note that this bug has been dismissed by upstream as NOTABUG for several years, since Gnome 2.6 IIRC. The keyboard layout selector was rewritten at that point - the old selector supported unlimited number of layouts, while the new one only supported at most 4 layouts.
-- Impossible to configure more the 4 keyboard layouts https://launchpad.net/bugs/56912 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
