I am having the same issues with audio… Premiere reports one dropped frame, but that’s not enough to make as much of a difference as I’m seeing here… or is it? I’m pretty sure the dropped frame is a false reading cause there’s one right at the beginning.
I think blaming defragmented harddrives and things is a bit premature these days.. if you have no other major apps running and a good system Premiere should be able to capture.