This is interesting -> I don't think Ctrl+S should be exiting editing in any form, can you describe this a little bit further? When you hit this is it:
a) moving to Preview (you can see the changes you made, but in preview mode not page view mode (the page tree won't be visible)
b) browser returns to the 'view page' (page tree visible), but your changes are not published (you may see a tag at the top "UNPUBLISHED CHANGES")
c) something else (please describe)
Second question: what does the browser's forward/back buttons display after the 'ctrl+S' result?