Very strange but I have researched this all over the web and so far have found no answer to this question. I even asked the law firm that is writing my patent application and they have hedged on the answer for weeks now! I know the answer is out there somewhere.
A method is a "process," and a system may be either a "manufacture" or a "machine" under 35 USC 101. The cases addressing the differences and the legal effect of these differences can be found dating back to the 1800's. There are some significant differences in how claims to methods and so-called "systems" can be enforced and what types of activities they can be used to preclude.