Icon missing on Publish form

We recently set up a site for a client so that they could upload an optional author/other photo for their blog posts. This field uses the nGen File Field type. When they upload a photo, they are not seeing the trash can icon, only a link to remove the image that doesn’t do anything when it is clicked.

This issue is occurring for them only when using computers at their office. I can see the icon and they can see it on their home computers.

Does anyone know what might be causing this?