Hi Community,
Since you are receiving API errors with respect to your posting attempts, it is indicative that eBay is preventing you from posting those items at this time for some reason. If the error is not explicitly stated on the "Events" page within your Auctiva account, please contact our customer support team and we'll be able to look up the exact error message returned by eBay for you.
You can contact our customer support team by completing the web form on the following page of our site:
http://www.auctiva.com/help/requesthelp.aspx-Mike