This is entirely identical - except that I've changed the document.domain to marlboro.edu. (Look at the page source.) Now the files that are accessible through the 'same-source' policy include anything within our domain.
Hmmm. I've also changed linkdetails.js to linkdetails2.js so that the script tries to access *.marlboro.edu even though this server is cs.marlboro.edu.
BUT this still doesn't work in firefox; I'm not sure why. I'm guessing this behaviour varies across browsers, and Firefox doesn't let you do this.