"You can take your Chicago Style Guide (though, actually the latest Chicago Manual of Style says both are acceptable but concurs that Strunk's interpretation is preferable), your MLA guide, your Harbrace Handbook, and you can subscribe to their false theologies of the possessive. I will not use the plural possessive with a singular noun, no matter what happens. It's right there, in the book, for all to see, and false prophets will not dissuade me. When I stand in Grammar Heaven, before the light-bulbed visage of William Strunk, Jr., he will not say to me 'Depart from me, ye cursed, into everlasting fire, prepared for the Grammar Devil and his angels.'"
-- Eric Burns over on Websnark again.
The debate is over the correct form of a singular possessive when the noun in question happens to end in 's.' Is it "princess's" or "princess'"? Or, in this specific case, "Eric Burns's" or "Eric Burns'"? Personally, I'm with the Snark on this one: "s-apostrophe" is for plural nouns.