oceanus,
To apply an Auctiva template to an active eBay listing, you need to recreate the item details section of the listing in Auctiva. Then, it can be applied to your active listing via the following process.
1) Recreate the item details section of your listing, which is everything before the Marketing Tools section on the lister page.
2) Save the listing by clicking the "Save" button.
3) Go to your Saved Listings folder, check the box next to the listing you created and click the "Get HTML" button.
4) Copy the html in the popup box.
5) Go to the corresponding eBay listing and click "Revise Item"
6) Click "Edit Description"
7) Click the "Enter your own html" tab on the description editor.
8) Paste the copied html in place of the html already there.
9) Save your changes.
I hope this helps=)
-Mike