Problem with photos

[olom]

Hi,

 

I have a problem with photos on my prestashop website. Recently I updated prestashop version to 1.6 newest. I use some application to import products and photos. After that update 7 new products has no photo: http://www.ksiegarnia.archidiecezja.wroc.pl/index.php?

 

Summary:

1. Photos and their thumbnails all exists in proper directory and can be accessed with proper link i.e.: http://www.ksiegarnia.archidiecezja.wroc.pl/img/p/2/7/4/2/2742-home_default.jpg

2. Photos are in administration panel, but there are no thumbnails. So photos are linked with products.

3. After thumbnail regeneration the same photos do not appear.

4. All caches are turned off

 

Have you got any idea why prestashop seems to not see images thumbnails? Thank you in advance for any suggestions.