Hi Heidi,
You did nothing wrong, however, your listing entitled "Adorable Fabric to create Bedding for your Baby" was unable to be posted successfully because your eBay token has become invalidated.
Please re-generate your eBay token by clicking the "Ebay Settings" link under the "My Account" tab, and then clicking the "Get New Token" button. Once you have campleted the token generating process, you should be able to post this listing successfully though your Auctiva account.
-Mike