K2 displays items only from Quickstart category?

Hello Everybody,
I ve installed GK Storefront from Quickstart. "Blog" - K2 page - shows only items from "fashion news" "style news", etc. those categories from GK Quickstart box. When disabling them - of course, first I've created some NEW K2 catagories and items - NO items displaying...Only menu on the left (all blog categories)
Regarding K2 items - Interesting is, there are 2 kinds of links: /blog/item (my new K2 items) and /template/k2/k2-categories (preinstalled - this works- ?).
Question is, how to control items in K2 in Storefront? I cannot do this. Changing sorting order, unpublish/republish items, categories, category ordering, no effect.
Please help!

Hi

You will find answers to Your questions in K2 documentation, but I think Your problem is that category settings are overwritten in menu item configuration if You select more than one category.