Volvo: transmission issues, automatic transmission cars, torque convertor

Question
My 2001 S60 seems to "jump" a bit on releasing the brake at a complete stop, and before applying the gas. My other automatic transmission cars do not do this; they slowly creep forward on release of the brake but do not jump. Is this a transmission issue or brake issue?

Answer
My first inclination would be the transmission, and more specifically the torque convertor.  On auto trannys, this sits between the engine and drive train to "smooth" the power transfer.  Malfunctions in this area can cause the symtoms you've described.  I would look there first.