not really, the point is that if you think your previous employer donīt like to make references for anyone or you worked just a few months for a company, donīt tell them, i mean, LIE! just give the telephone number, email, address, name of your former manager, and that is!!!!
i think they donīt call them.
regarding personality tests......... if they ask you: you get upset for silly things? answer: no!! things like that, donīt be naive like me!!