Then I created a new article for each of the folders: -gallery rows=2 cols=3-folder1/folder2-/gallery- et voilà: It works!
Simple as that, I got a gallery with 3x2 thumbnails that open a slideshow when you click on one of them!
Perfect for my needs and very fast and quick to use!
I used phoca gallery before on joomla 1.5 und 2.5, but that was a bit overkill for my needs. I just needed 40 galleries with the same layout without fance configuration!
Thank you for this amazing plugin!
(By the way, I used this extension on a dog kennel website, the galleris where for each week of the litters and each of the dogs)