Hi Tim2001,
When you post a store listing with a duration of "Good til Canceled", they will actually be treated as 30 day store listings that automatically renew every 30 days unless they sell or are ended by the seller. Therefore, I believe you will find that these items relist automatically after the initial 30 days if they have not sold yet.
If you have any additional questions or concerns regarding your Auctiva account, please feel free to 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