youpickedawinner,
There's currently no way to change the title of an Auctiva store listing. Even if you have changed it on eBay, it will remain the same.
If you would rather this listing, with the incorrect title, not be displayed in your Autiva store, you can make it hidden at Auctiva -> Store(tab) -> Edit Items. Items that are made hidden will no longer be displayed in your Auctiva store, nor will they be displayed in your store window the next time it refreshes, which it does about every 2 hours.
-Mike