Classifieds Featured Image Button Not Working

Hi,

I just installed the classifieds plugin and it's awesome! I'm just experiencing one problem.

When I try to add an ad in the front-end, the featured image button doesn't work. It's clickable but nothing happens. For some reason when you click on the empty space underneath the button, the file browser opens to upload the image. The invisible space underneath the button is like 10px heigh.

Could someone please help me out.

Thanks a lot!!