First of all let me thanks everyone who make possible to have this huge Drupal web. This is a start point without rival to newcomers on Drupal.
I have installed the module BG without any trouble (I´m almost sure as the module works) following the vacilando´s web indications and activating BG tag on filters. I made numberless tries trying to find out what is going NOK without success, doing modifications step by step on every possibility on the admin section via try and error system, activating/desactivating modules could make appear the issue, etc, but I can not solve and fix the issue. I have reviewed the BG issues and there is any similar one.
This issue, as you will see on the attached .jpg file (where appear the aspect of the web I am doing tries on local before launch it in production), is that BG works fine (everything is OK as per my indications on the nodes), the images pop up once clicking and slide properly, but I can not see the thumbs. The only thing that appear is a "X thumb".
I have not idea what is going on...
Thanks in advance for your help !