Think about the store categories in your Auctiva Store like filters buyers can use to narrow down the items in your store to what they are interested in. So when they first come to your store page, they will see all your items displayed on one page, then they click on the category links to filter those items (for example, display only "guitars.")
To determine which items will be displayed when they click on a category link, use the Keywords. The keywords that you set for the category when you created it on theedit store searches page are basically used to search the titles of your auctions. So if you had "strap" as a keyword for the "Accessories" category, whenever a user clicks on that link it will search your item titles for the word "strap" and display those.
You can enter in any number of keywords for a category up to 30 characters total, seperated by commas. So in this way you should be able to customize it to the point that all the items you want show up for the given category.
If you don't create your own custom categories, we will generate some for you automatically based on the eBay categories your items are listed in.
Sorry I misunderstood your question before, let me know if I answered it satisfactorly this time
-- Auctiva David