Javascript error: cannot read property classname

Hi 

I have recently started seeing this error from your widgets.js file:

1. Uncaught TypeError: Cannot read property 'className' of null widget-1.4.gz.js:1

1. UE.Element.removeClassNamewidget-1.4.gz.js:1

2. d.onloadwidget-1.4.gz.js:1

You can see the error at http://easybacklog.com

Do you know what is causing it?

Thanks,

Matt