just tested in Gnome: add Spanish, reboot, add new user. Now I have two users, desktop languages for both are Spanish. Login to user 1, run localedrake (Sistema -> Centro de control: Otras -> Ajustes regionales) set to English and logout, that should be it for this user. But it doesn't work (also not after a reboot). => Problem with localedrake in Gnome and other non-KDE DEs? KDE works fine.