Hi,
Active listings on Bbay have only a limited Revise capability from Auctiva using the Revise button or Add Images on the Active Listings page. It sounds like you want to change or add to text in the Description.
To do extensive revisions like adding or change to text etc., use eBay's Revise listing from your active listing on ebay. You can always use that method, and I personally opt for that as the most direct, fully functional on all levels, and immediately verifiable. Auctiva, afterall, is linked to eBay's system (separate and distinct systems as a 3rd party provider to you), i.e. not where the listing is currently ACTIVE.
Danno