Hi JDUBB,
Thanks for letting us know about this. Based on the API error message you are receiving, it sounds like the combined shipping rule that we are sending to eBay along with your listings is no longer valid, which could have happened if you changed your combined shipping rules on eBay recently and have yet to update them within your Auctiva account.
Assuming this is the case, you should be able to resolve the problem with respect to future listings by updating your combined shipping preferences within Auctiva. This can be done by mousing over the "My Account" tab within your account, selecting the "eBay" option under "Settings", and then clicking the "Update Combined Shipping Discounts from eBay" button on the ensuing page.
If you continue to receive this error with new listings you post after doing this update, I recommend filing a support request about the issue using the form on the following page of our site:
http://www.auctiva.com/help/requesthelp.aspx#-Mike