CSS Class Names not saving

Hi

I'm trying to style some multi choice radio buttons using this method;

http://www.rocketgenius.com/survery-style-multiple-choice-fields-with-gravity-forms/

I have around a dozen or so consecutive questions, but only the first question saves the CSS Class Name in the field. When I add it in the second, and update the form, the class is romved from the field when I check it. It looks like a bug to me? Anybody else having this issue?

Thanks

I've worked out that it's the mouse action the from doesn't like. A right click and paste and select paste will not save, whereas a ctrl +v paste will. Bizarre, but sorted anyway.