OK... I set up a dummy board on my remote site and ran the install script again.
I now have a Facebook control panel page in my UCP, but no FB login link or button is present on the main (or any other) page on either FF or Chrome - perhaps I am misunderstanding the function, and please correct me if I am incorrect, but I had thought there would be an FB login button somewhere at the top of each page such as you have on your own site. Anyhow, the UCP appears like this:
I suspect this is good...
However, when one uses that "Enable Facebook Login" button, the FB dialogue popup appears and one fills that in, and then in Chrome this happens:
You can see that the whole page is somehow suppressed in clarity, and then there's that funky white area... In FF however, this happens:
In other words, a page within a page (with the funky white area behind it)! Then in both browsers, after a few moments, they resolve to this:
...which is a "rotating world" that shows hits to the page, which is normally located towards the bottom left part of the page. There's nothing else on the page at all!!