Timethief, I FINALLY figured this out. After updating FF to 9.x, I still couldn't see the Update button. By dumb luck, my mouse pointer was hovering over the word Publish (just below the content) and had turned into this 4-point arrow icon. I clicked it for some reason and noticed when I did that the Update button appeared!! This apparently is a toggle button to display (or hide) the Update button. I don't even recall clicking that in the past (and don't know why I would have).
So, if anyone else runs into this problem, look just below the content window of the page you're on and look for the word Publish. Click it to either display (or hide) the Update button. Sometimes it's the simplest things :(
Anyway, thanks for all your help in trying to resolve this.