Thank you! Your comment steered me to the solution.
On machine #2 (no save) I would always end up with two IDE windows open... the original small 'no-file-open' window, and also a window, larger and positioned differently as I wanted.
All I had to do in this case is CLOSE the original small window before quitting altogether. The IDE then saves all the details of the newer window.
DOH! I knew it would be simple!
-Richard