Hi, thanks for replying :-)
Strange, it definitely fails to validate on mine. If I remove the dash from "wis-wander" then validation is successful.
I've tested in Firefox 20.0.1 and Google Chrome 26.0.1410.64 m and get the same result.
I'm using Contact Form 7 version 3.4.1 on a Wordpress 3.5.1 installation with the default jQuery 1.8.3, and jQuery UI Core 1.9.2