ImageCache module does not work properly with drupal 7 & ubercart modules

Hi.
i'm using drupal 7 on my website including ubercart module installed on it (http://feshal.com).
in the default drupal installation everything works good.

the problem is that when i want to use drupal's multisite feature to have another site (shot.feshal.com) product images didn't upload in the right place (on second site). and so product images are not displayed.

it seems this is the problem of the ImageCache problem because no image styles are created for the product image.
i have the same isues with the drupal 6.x

i have attached some screen shots.
please help...