I did not check or un-check this box after installation. It was unchecked which sounded like what I want. The label says:
Force SSL Exclusively
and the description says:
Posts and pages without Force SSL enabled will be redirected to HTTP.
so to check the box makes it sound like it will force the whole site to be SSL (not what I want). However, I just gave it a try to see what it would do and it now does what I want, that is, only the one page that I specify as HTTPS is HTTPS.
I think this needs better documentation.
Thanks,
Steve