Hi Dennijol,
The scrolling gallery is set to display 14 of your active listings at a time and is refreshed every 4 hours. Each time the store window refreshes, it is populated with another 14 of your current listings that are ending around the same time as the next auction of yours that is viewed. If a perspective buyer clicks the link on the bottom-right of your scrolling gallery, he/she will be directed to your Auctiva store, which displays all of your active listings at any given time.
It is actually not possible to place your Auctiva store categories on your scrolling gallery. Therefore, in order to access your Auctiva store categories, your buyers would need to click the link in the bottom-right of your scrolling gallery to reach your Auctiva store, and then search your Auctiva store categories from there.
If you have any additional questions or concerns, I recommend filing a support request using the appropriate link on our help page:
http://www.auctiva.com/free-auction-software-help/help.aspx-Mike