Description
If you first click on the extra image and then zoom over the main image, then the zoombox shows the extra super image and not the main super image:
 
Solution
Download the updated version of the files:
http://www.viart.com/downloads/block_product_details-4.0.8.zip
http://www.viart.com/downloads/images-4.0.8.zip
 
Further, extract 'block_product_details.php' into 'blocks' folder and 'images.js' file into 'js' folder of your shop replacing existing files. Please do not forget to make a backup copy of the current files in case something goes wrong.