After upgrading to Ubuntu 14.04, the 0, 4 and 6 keys in my numpad suddenly respond only after being pressed for about a second. The rest of the numpad is fine, as well as the 0, 4 and 6 above the letters. My computer is a laptop (Vaio). I checked the slow keys option in the universal settings, that's not it.
Update: Turns out this problem applies only to my main (administer) acount. It doesn't happen in the login screen or a guest session.