I'll see what i can discover with the Firebug version you recommended.
Oddly enough, I opened the site a few minutes and the code is there now.
I guess i should have added that the site is
http://html5.jonathandevelop.com/.
Its an HTML 5 Game book i'm going thru,
"HTML 5 Games: Creating Fun with HTML5, CSS3, and WebGL" by Jacob Seidelin
Apparently its a tough problem to reproduce.
I think a similar problem is going on in Google Chrome, but I cannot be sure.
I wonder if its something on my Windows 7 machine. I ran Spybot S & D last night...
Thanks anyway.