Thanks, ZenBrian...great idea I didn't think of. I found that if I hit Ctrl - a few times (6 or 7) it will eventually get everything so tiny that I can see the box with the Share on Facebook button. Of course, everything is too small to read, but at least I can see the button and click it. Its a good workaround, but still, something isn't right.
Apparently, I'm the only one with this issue....which seems unlikely, but possibly the case.