Textism's Refer PHP app

Has anyone had any luck with the referral tracking app from Textism called Refer? (http://textism.com/tools/refer/) I just tried messing around with it but ran into a wall when setting the .htaccess file; this might be (I suspect) because I already have a file set up to control Movable Type’s dynamic (and PHP-based) page loading, or perhaps because my index pages are .SHTML files. Or maybe it’s simply because I’m a nincompoop and set everything up wrong. Any tips would be appreciated.