Hi thank you for your response. The solution what you are suggesting is to create a menu item for each K2 category which is extremely user unfriendly. As you can see there are lots of K2 categories with many parent categories, so every change of the category would mean to change the menu item which is horrible and causes differences (mistakes).
That's the reason why I use separate (3rd party) module for listing all the categories and I didn't have any idea that your module doesn't work without separate menu items.
Is there any solution to solve the situation. I'm sure that you as experienced joomla guys know lots of tricks..
Ladislav