Verification: Dan, you are saying that the 950 is doing something that the Chiro is sensitive to, but which the Stratos is not sensitive to? The Chiro will thump on any channel to which it is connected and the Stratos will not thump on any channel?

If so, and if we knew what the Chiro and Stratos were doing differently in their input stages, this would seem like a great clue as to the nature of the problem.