Ah! Alas! This is what I get for not testing the demo on any other computers other than my Windows 7 laptop. I’ll see if I can get the same error on an XP computer, nail down a fix, and get back to you.
Sorry for the problem, and thanks for giving me a heads-up.
UPDATE: It was just a screen resolution problem. Here’s a link to the fixed version of the demo. I tested it on a grand total of TWO different computers and it worked OK.