That did work, Start8 now behaves correctly on the 2nd monitor, which is a relief.
However I'd really prefer Start8 to work with DisplayFusion because I use DisplayFusion to get other behaviours and settings, e.g. to limit taskbar icons to display only if the window is on its respective monitor (which doesn't work on 8.1 even though taskbar properties suggest is should) and different wall paper on each monitor.
Please would you fix it so that Start8 works with DisplayFusion?
Thanks.