I have tried with the supplied files and although the error is gone, the popup image is still a normal browser window and I only see one image on the product description.
I then used Winmerge to compare the supplied files with my own configure.php and product_info.php and the error was back (!).
I have one question though, How do I insert the additional images in the product description page? I mean when I click a product, it shows my STS product template with only one clickable image ( pops up with a normal firefox window).
Can you please help? thanks once again!