Can you ad link to your page and the polish translation, thank you by the way.
What version of the plugin are you using? try also refreshing your permalink structure just by re-saving your options.
There was a change in how permalinks are refreshed on WP 3.3 (I think) and it is an issue with the plugin, I notice that when I was working on the new version of the pluign.
You can try using Image Store 3.0 RC1 but I am still testing it for any potential bugs.