I again have a chair and a cargo bay which won't move relative to each other, regardless of which part is moved or which tool is used. This time however, the cargo bay (which was at 0,0,0) and chair somehow moved 18m forward as I adjusted parts attached to it -- the airship envelope. When I moved the cargo bay back to 0,0,0 by entering numbers, the chair stayed 18m forward of where it had been. Subsequent adjustments again move chair and cargo bay together.
