Featured image problem

Hi, i have one problem with featured images. When i upload new image from my computer and put at features, i see that this is not displayed,but displayed image with size 1x1px with grey color, this color i think is pick up from image who i upload to the server, i think that script resize image in other image with size 1×1 px. Why? Intersting is that when i upload an image how was transfered to webserver with site (i put when i testing site to localhost) image work veri nice in all scripts but when i upload with wp-admin i donțt know why i see an image with size 1x1px and color, sorry for my english 🙂

a link to this site —- > http://shop.rucksack.ro/

http://wordpress.org/extend/plugins/woocommerce/