Hi Phil,
The behavior you have described is actually fairly normal, regardless of which application you are posting your listings through. Once a listing is posted through Auctiva and is assigned an item number, it is entirely in eBay’s hands to "index" the listing to appear in the appropriate search pages, which can take as long as 6 hours.
Additional information on this fairly common eBay issue is available on the following page of eBay’s help index:
http://pages.ebay.com/help/find/questions/wheres-my-item.html. If you have any further questions about this specific issue, I recommend contacting eBay’s customer support department.
Any additional questions or concerns? Please feel free to contact our customer support team using the appropriate link on our help page:
http://www.auctiva.com/free-auction-software-help/help.aspx-Mike