FYI,
While after days of trying, I still can't figure out what happened, I did find a fix.
https://addons.mozilla.org/en-US/firefox/addon/11481
It's a Firefox PlugIn that forces FF to Show Alternate Text as a Tooltip.
I still don't know if vBulletin changed their code or if I F-ed something up by installing FCleaner. But a few days ago, the convenient yellow tooltip popup windows that show when you mouse over a pic just quit being there.
When I'm perusing pics, I pretty much won't click on anything smaller than 200k unless it's something really special. I hate low res pics and with today's cameras, there's no excuse for all this 50k crap out there.
Now at least I'm back to where I can tell the difference without having to load the pic! Hope this helps somebody else!
DD