Yep! Chalkboard.XAR opens without an error on my PC. Then again, Josè might be on to something with MS Internet Explorer. I downloaded the files using Firefox v3.6.4 and don't seem to be having an issue.

FWIW, it's been 7-8 years (!) since I've used IE for web browsing. I bounce around between Firefox, Opera, and Google Chrome depending on my mood and what I'm doing.