Hi Lona,
I’m not sure what caused this but I’ve informed our engineering department of this for investigation.
In the mean time, to remove the store window from your active listings you must delete the store window html from the html description using eBay's "Revise Item" form. The html description can be found at Auctiva -> Store -> Store Window -> Store Window HTML. The store window html lies between ASW tags.
I apologize for the inconvenience
-Mike