There is a bug where if you type a title that gets converted to a slug (using default settings), and then modify the slug and then tab out. if you're using default settings all your dashes will be removed. I added to the map "2d":"-" which will replace dashes with dashes which works well for if your editing the title and also if you're editing the slug
The refactored code is adapted from "jQuery Slugify a string!" from Pablo Bandin http://tracehello.wordpress.com/2011/06/15/jquery-real-slugify-plugin/ Dual licensed MIT / GPL
… plugins should.