Ok I understood. Thank You very much for the answer!

Just for information: if the file touch.jquery.js is copied from version 3.3.4 to the new 3.4.4 version everything is ok!

The file that was the problem it is touch.jquery.js in the folder /js

Here is another example of a Image Store user.
http://iwphoto.co.uk/galleries/bennett-m/
Click on the first image to start the lightbox.
In the first picture we can clearly see the buttons “Add to Cart” and “Select”.
Now click on “Next” arrow, so passing to the next photo no more buttons “Add to Cart” and “Select”.
This problem is repeated for each new thumbnail page!

Sorry…
Thank you for the reply …
I tested on Firefox v. 27, 11 IExplorer v. 11, Chrome v. 33, and it’s always the same, no button for each second image on each page of thumbnail

starting from the first image on the lightbox …

Here are the links …

1)First page of thumbnails everything is OK
https://dl.dropboxusercontent.com/u/68937407/01.JPG

2)Here we are in the lighbox on the first image and everything is OK …
https://dl.dropboxusercontent.com/u/68937407/02.JPG
So now you click on the Next button and…

3)…here we are in the lightbox on the second image, and no button select or add to cart
https://dl.dropboxusercontent.com/u/68937407/03.JPG

For all the others images is ok!
And when we go to the next page it again the same thing … No button (add to cart or select) for the second image starting from the first image on the lightbox….