I installed Image Handler 2 on Zen Card 1.3.7

Image Handler seems to work fine. Everything is good until i try to add more pictures in a product (via admin/tools/image handler 2)
I see categories, i select product, i am going to add pic.
When i select the images and click to save i get the message:


You don't have permission to access /admin/image_handler.php on this server.

Why i don't have permission? image_handler.php works fine until i save new pictures...
Please help! I am stuck...