In this test page, I have reproduced my
afi.cat/labcr/index.php?option=com_content&view=article&id=96&Itemid=187&lang=ca .

When I open the gallery, the thumbnails strip should appear below the image, but instead of that, it appears on the left on only shows one thumbnail.

Thanks for your help.

This is because highslide pop up engine conflicts with your template.
That is why we add so many pop up engines... Please select another one.

Yes but, is there a way to show the thumbnails below the big image using any other pop up engine?

Please try all the pop up engines so as to find which one is closer to what your are looking for and of course has no conflicts...

The only one who cause conflicts is the highslide pop up engine. So, if I can not use it, I'd like to know any way to put the thumbnails strip below the image.

The rest of engines are really pretty, but the default behavior with the thumbnails is "invisible" or "over the image". I'd like "below the big image".

Is it not possible?  ???

You may select one that it is closer to your preference and write some css overrides in order to have the result you want...