Hot-Lightbox/ Navigation buttons are invisible

I've copied and published the hot light-box as user2, but in this case all navigation button are not there. Any idea how to solve this?

open:

modules\mod_hot_lightbox\js\jquery.lightbox-0.5.min.js

in compressed JavaScript code you will be able to recognize urls like this:

...:'modules/mod_hot_lightbox/images/li...

first try to pub / in front of that relative paths:

...:'/modules/mod_hot_lightbox/images/li...

if that does not help use absolute paths:

...:'<you joomla base link>/modules/mod_hot_lightbox/images/li...