It might be country/industry dependent then.

I've been working as a programmer for 9 years now and had 5 jobs during that time - out of all interviews I've went to throughout the years only one interviewer ever (fairly casually) asked me what my previous salary was.

Because I felt like I was under-payed in my previous job I told him I earned 2k more a year than I actually did and asked for a salary that was 7k a year more than that sum.

He eventually gave me a slightly lower offer for 5k more than my supposed previous salary (and 7k higher than my real previous salary) but I ended up going for another company altogether.