Sounds like lympho to me. It has become more and more common lately in the trade from what I've seen. Basically, it's usually not a huge deal health wise, but it is contagious (I believe it's a virus and I don't know of any treatments) and creates those unsightly bumps. Usually the fish fights off the infection after a month or two, but often the bumps will remain and must be removed surgically (read: sterilized razor blade for us DIY types).
I believe I read somewhere up to 70% of fish in the hobby have been exposed to it... A lot of the time they just won't show symptoms. Maybe someone on here with more knowledge on it can give a more scientific explanation.