"A famous difference in many versions of the story is the "glass slipper." Authorities on fairy tales (who you tend not to see at parties) disagree about whether Perrault's slipper was made of glass or fur, as the words in French (verre and vair respectively) are pronounced almost the same. It's kind of important, because if the Prince was wandering the land looking for a lady with the perfect "fur slipper" ... well, it doesn't take Freud to figure that one out, and suddenly the Prince doesn't look so noble."
http://www.cracked.com/article_15962_p5.html