After a while, you get a *gut feeling* for this sort of stuff, and my gut was telling me; it's a plugin issue. Why?
First thing I did was look in these forums, to see if anyone else was having a problem with Flash. Seeing nothing, I started this thread, then did some forensics.
Flash appeared be be installed, but my browsers weren't recognizing the SWF plugin.
In my rush to try Lightspark, that's about as far as I got into investing the problem -- Facebook was calling me -- and I needed to get Flash (any Flash) working. Adobe Flash won the toss...
Kinda sad how much we depend on an orphaned app, eh what?!?!?