So, I have a website with an autoFontSize script (Got it from stackoverflow, but slightly edited it too loop over each div with that specific class)

(function ($) {
    $.fn.textfill = function (options) {
        this.each(function () {
            var fontSize = options.maxFontPixels;
            var ourText = $('h2 a', this);
            var maxHeight = $(this).height();
            var maxWidth = $(this).width();
            var textHeight;
            var textWidth;
            do {
                ourText.css('font-size', fontSize);
                textHeight = ourText.height();
                textWidth = ourText.width();
                fontSize = fontSize - 1;
            } while ((textHeight > maxHeight || textWidth > maxWidth) && fontSize > 16);
        });
        return this;
    };
})(jQuery);

$(document).ready(function () {
    $('.fotonode.fotopagina').textfill({
        maxFontPixels: 30
    });
});?

And a (simplified) HTML structure:

<div class="fotonode fotopagina">
  <h2><a href="#">Testing Title</a></h2>
</div>

For some reason this doesn't work (neither locally nor live) BUT it does work on JSfiddle: http://jsfiddle.net/Yb9yj/

I read somewhere that this can cause problems. I copied the code from jsfiddle to my file, so maybe I have (unintentionally) copied some white spaces that shouldn't be there or something. I don't know. But how can I solve this then?