Generating images problem

[JTT]

I have a problem in V.1.4. when generating images - for example when I add new product.

When I add an image to product, I get images in img/p folder like :
25-83.jpg
25-83-small.jpg
25-83-large.jpg
25-83-home.jpg
etc.

and I miss 25-83-productlist.jpg image. And I do not see the image in the product list...
Where can be the problem ? THanks !